7Baggers

Unitil Corporation
(NYSE:UTL) 

UTL stock logo

Unitil Corporation, a public utility holding company, engages in the distribution of electricity and natural gas. It operates through three segments: Utility Gas Operations, Utility Electric Operations, and Non-Regulated. The company distributes electricity in the southeastern seacoast and state cap...

Founded: 1984
Full Time Employees: 505
Sector: Utilities
Industry: Utilities-Diversified

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Quarterly
Annual
    Unit: USD2026-03-31 2025-12-31 2025-09-30 2025-06-30 2025-03-31 2024-12-31 2024-09-30 2024-06-30 2024-03-31 2023-12-31 2023-09-30 2023-06-30 2023-03-31 2022-12-31 2022-09-30 2022-06-30 2022-03-31 2021-12-31 2021-09-30 2021-06-30 2021-03-31 2020-12-31 2020-09-30 2020-06-30 2020-03-31 2019-12-31 2019-09-30 2019-06-30 2019-03-31 2018-12-31 2018-09-30 2018-06-30 2018-03-31 2017-12-31 2017-09-30 2017-06-30 2017-03-31 2016-12-31 2016-09-30 2016-06-30 2016-03-31 2015-12-31 2015-09-30 2015-06-30 2015-03-31 2014-12-31 2014-09-30 2014-06-30 2014-03-31 
                                                     
      operating revenues
                                                     
      electric
    65,500,000 60,900,000 64,300,000 51,000,000 60,200,000 55,800,000 62,500,000  73,600,000 61,700,000 72,100,000 64,500,000 108,200,000 78,700,000 75,700,000 54,300,000 89,200,000 66,300,000 65,500,000 56,600,000 60,100,000 42,575,000 59,900,000 50,200,000 60,200,000 44,250,000 60,400,000 51,800,000 64,800,000 41,900,000 61,400,000 48,700,000 57,500,000 38,600,000 57,500,000 47,400,000 49,500,000 45,700,000 55,200,000 44,100,000 51,100,000 47,900,000 51,400,000 48,400,000 70,300,000 56,500,000 54,200,000 46,100,000 61,900,000 
      gas
    151,400,000 100,600,000 36,800,000 51,600,000 110,600,000 71,700,000 30,400,000  105,100,000 67,900,000 31,800,000 38,900,000 112,000,000 82,800,000 34,500,000 44,600,000 103,400,000 73,500,000 32,600,000 40,000,000 78,700,000 32,850,000 27,500,000 33,700,000 70,200,000 35,975,000 24,900,000 32,600,000 86,400,000 36,850,000 25,700,000 34,700,000 87,000,000 32,975,000 25,100,000 32,000,000 74,800,000 57,100,000 22,100,000 28,900,000 73,100,000 53,000,000 21,700,000 27,600,000 100,300,000 62,100,000 20,900,000 25,800,000 92,600,000 
      total operating revenues
    216,900,000 161,500,000 101,100,000 102,600,000 170,800,000 127,500,000 92,900,000  178,700,000 129,600,000 103,900,000 103,400,000 220,200,000 161,500,000 110,200,000 98,900,000 192,600,000 139,800,000 98,100,000 96,600,000 138,800,000 75,425,000 87,400,000 83,900,000 130,400,000 80,450,000 85,300,000 84,400,000 152,100,000 79,625,000 88,200,000 84,500,000 145,800,000 72,700,000 84,000,000 80,800,000 126,000,000 104,300,000 78,800,000 74,500,000 125,800,000 102,400,000 74,700,000 77,500,000 172,200,000 119,800,000 76,600,000 73,300,000 156,100,000 
      operating expenses
                                                     
      cost of electric sales
    35,900,000 32,700,000 31,200,000 25,200,000 32,700,000 30,200,000 32,800,000  46,500,000 37,700,000 42,900,000 40,300,000 81,500,000 56,500,000 47,300,000 30,700,000 64,600,000 42,300,000 40,100,000 32,300,000 36,400,000 25,075,000 35,400,000 27,800,000 37,100,000 26,600,000 35,300,000 29,400,000 41,700,000 24,275,000 35,500,000 26,400,000 35,200,000 21,075,000 32,700,000 24,100,000 27,500,000 23,700,000 29,600,000 23,700,000 31,000,000 26,300,000 29,200,000 27,900,000 49,100,000 36,400,000 31,600,000 27,200,000 42,700,000 
      cost of gas sales
    69,300,000 36,200,000 10,200,000 14,400,000 39,700,000 20,400,000 7,100,000  44,100,000 19,800,000 9,600,000 9,600,000 57,100,000 39,500,000 14,100,000 16,400,000 51,400,000 32,600,000 13,200,000 15,000,000 30,900,000 12,025,000 9,500,000 10,800,000 27,800,000 14,600,000 6,200,000 9,300,000 42,900,000 16,750,000 8,100,000 11,800,000 47,100,000 14,150,000 8,300,000 11,500,000 36,800,000 25,200,000 6,100,000 9,100,000 37,200,000 24,200,000 5,500,000 9,500,000 61,500,000 32,700,000 5,700,000 9,500,000 56,100,000 
      operation and maintenance
    23,400,000 26,700,000 21,900,000 21,300,000 22,600,000 20,500,000 20,300,000  18,200,000 19,600,000 19,600,000 18,300,000 18,100,000 18,200,000 18,600,000 18,400,000 18,500,000 17,500,000 16,700,000 17,500,000 17,000,000 12,150,000 16,100,000 14,600,000 17,900,000 12,475,000 15,500,000 15,900,000 18,500,000 12,875,000 16,400,000 17,800,000 17,300,000 13,250,000 17,800,000 17,600,000 17,600,000 17,700,000 15,500,000 15,700,000 17,400,000 17,100,000 16,800,000 16,300,000 16,900,000 15,300,000 16,900,000 15,300,000 17,100,000 
      depreciation and amortization
    23,300,000 23,000,000 22,200,000 21,800,000 21,700,000 20,900,000 19,100,000  18,000,000 17,300,000 16,800,000 16,600,000 16,700,000 15,700,000 16,600,000 14,800,000 15,500,000 15,000,000 14,800,000 14,800,000 14,900,000 10,175,000 13,700,000 13,500,000 13,500,000 9,750,000 12,800,000 12,400,000 13,800,000 9,350,000 12,400,000 12,700,000 12,300,000 8,800,000 10,800,000 11,900,000 12,500,000 11,500,000 11,600,000 11,700,000 11,800,000 11,600,000 11,400,000 11,300,000 11,400,000 10,900,000 10,800,000 10,200,000 10,200,000 
      taxes other than income taxes
    9,100,000 8,200,000 8,600,000 6,600,000 7,900,000 7,300,000 7,800,000  7,700,000 7,400,000 7,000,000 6,800,000 7,300,000 6,000,000 6,400,000 6,700,000 6,800,000 6,000,000 6,100,000 6,200,000 6,200,000 4,475,000 5,300,000 6,100,000 6,500,000 4,250,000 5,500,000 5,100,000 6,400,000 4,125,000 5,500,000 5,200,000 5,800,000 3,900,000 4,900,000 5,200,000 5,500,000 4,900,000 4,900,000 4,800,000 5,000,000 4,700,000 4,500,000 3,600,000 4,900,000 4,400,000 4,200,000 4,000,000 4,600,000 
      total operating expenses
    161,000,000 126,800,000 94,100,000 89,300,000 124,600,000 99,300,000 87,100,000  134,500,000 101,800,000 95,900,000 91,600,000 180,700,000 135,900,000 103,000,000 87,000,000 156,800,000 113,400,000 90,900,000 85,800,000 105,400,000 63,900,000 80,000,000 72,800,000 102,800,000 67,675,000 75,300,000 72,100,000 123,300,000 67,375,000 77,900,000 73,900,000 117,700,000 61,175,000 74,500,000 70,300,000 99,900,000 83,000,000 67,700,000 65,000,000 102,400,000 83,900,000 67,400,000 68,600,000 143,800,000 99,700,000 69,200,000 66,200,000 130,700,000 
      operating income
    55,900,000 34,700,000 7,000,000 13,300,000 46,200,000 28,200,000 5,800,000  44,200,000 27,800,000 8,000,000 11,800,000 39,500,000 25,600,000 7,200,000 11,900,000 35,800,000 26,400,000 7,200,000 10,800,000 33,400,000 25,300,000 7,400,000 11,100,000 27,600,000 22,000,000 10,000,000 12,300,000 28,800,000 22,200,000 10,300,000 10,600,000 28,100,000 23,600,000 9,500,000 10,500,000 26,100,000 21,300,000 11,100,000 9,500,000 23,400,000 18,500,000 7,300,000 8,900,000 28,400,000 20,100,000 7,400,000 7,100,000 25,400,000 
      yoy
    21.00% 23.05% 20.69%  4.52% 1.44% -27.50%  11.90% 8.59% 11.11% -0.84% 10.34% -3.03% 0.00% 10.19% 7.19% 4.35% -2.70% -2.70% 21.01% 15.00% -26.00% -9.76% -4.17% -0.90% -2.91% 16.04% 2.49% -5.93% 8.42% 0.95% 7.66% 10.80% -14.41% 10.53% 11.54% 15.14% 52.05% 6.74% -17.61% -7.96% -1.35% 25.35% 11.81%     
      qoq
    61.10% 395.71% -47.37% -71.21% 63.83% 386.21%   58.99% 247.50% -32.20% -70.13% 54.30% 255.56% -39.50% -66.76% 35.61% 266.67% -33.33% -67.66% 32.02% 241.89% -33.33% -59.78% 25.45% 120.00% -18.70% -57.29% 29.73% 115.53% -2.83% -62.28% 19.07% 148.42% -9.52% -59.77% 22.54% 91.89% 16.84% -59.40% 26.49% 153.42% -17.98% -68.66% 41.29% 171.62% 4.23% -72.05%  
      interest expense
    10,800,000 9,400,000 8,900,000 9,300,000 9,100,000 7,200,000 7,400,000  7,300,000 7,600,000 7,000,000 7,000,000 7,100,000 6,400,000 6,600,000 6,300,000 6,200,000 6,100,000 6,500,000 6,300,000 6,700,000 6,100,000 5,600,000 5,900,000 6,200,000 5,800,000 5,800,000 5,900,000 6,200,000 6,100,000 6,000,000 5,900,000 6,000,000 6,000,000 5,800,000 5,300,000 6,000,000 5,800,000 5,500,000 5,700,000 5,500,000 4,600,000 5,500,000 6,000,000 5,800,000 5,400,000 5,000,000 5,300,000 5,200,000 
      other expense
     -100,000 -300,000 -700,000 100,000 100,000 -300,000  300,000 -25,000                                        
      income before income taxes
    45,100,000 25,400,000 -1,600,000 4,700,000 37,000,000 20,900,000 -1,300,000  36,600,000 20,100,000 1,000,000 4,900,000 32,400,000 18,700,000  5,000,000 28,900,000 19,100,000 -300,000 3,400,000 25,400,000 18,000,000 700,000 3,800,000 19,900,000 15,000,000 3,200,000 5,100,000 34,700,000 14,400,000 3,200,000 3,400,000 20,400,000 17,600,000 3,700,000 5,100,000 20,100,000 15,400,000 5,500,000 3,700,000 17,900,000 14,600,000 1,800,000 2,800,000 22,500,000 14,600,000 2,300,000 1,700,000 20,100,000 
      provision for income taxes
    11,900,000   700,000 9,500,000 5,300,000 -1,300,000  9,400,000 4,600,000 -400,000  8,300,000                                     
      net income applicable to common shares
    33,200,000 19,000,000 -300,000 4,000,000 27,500,000 15,600,000   27,200,000                                         
      earnings per common share – basic and diluted
    1,850,000 472,500 -20,000 250,000 1,690,000 490,000   1,690,000                                         
      weighted-average common shares outstanding – basic and diluted
    17,900,000  17,000,000 16,200,000 16,200,000  16,100,000  16,100,000                                         
      income tax expense
     2,225,000 -1,300,000                           1,250,000 400,000   2,775,000 1,400,000 2,000,000  2,550,000 2,000,000 1,200,000  2,525,000 100,000 1,100,000  2,200,000 700,000   
      electric and gas operating revenues
                                                     
      billed and unbilled revenue:
                                                     
      residential
           30,400,000                                          
      commercial and industrial
           26,300,000                                          
      other
           2,100,000                  225,000   900,000 875,000 1,100,000 1,100,000 1,300,000 1,125,000 1,400,000 1,400,000 1,700,000 1,500,000 1,500,000 1,500,000 1,600,000 1,500,000 1,600,000 1,500,000 1,600,000 1,200,000 1,500,000 1,400,000 1,600,000 
      total billed and unbilled revenue
           58,800,000                                          
      rate adjustment mechanism revenue
           -2,400,000                                          
      total electric and gas operating revenues
           56,400,000                                          
      allowance for doubtful accounts
           2,200,000                                          
      accrued revenue
           2,024,000,000                                          
      regulatory assets – current
           61,100,000                                          
      unbilled revenues
           4,800,000                                          
      total accrued revenue
           65,900,000                                          
      exchange gas receivable
           2,024,000,000                                          
      northern utilities
           5,400,000                                          
      fitchburg
           400,000                                          
      total exchange gas receivable
           5,800,000                                          
      gas inventory
           2,024,000,000                                          
      natural gas
           100,000                                          
      propane
           200,000                                          
      liquefied natural gas & other
           100,000                                          
      total gas inventory
           400,000                                          
      regulatory assets consist of the following
           2,024,000,000                                          
      retirement benefits
           26,800,000                                          
      energy supply and other rate adjustment mechanisms
           57,300,000                                          
      deferred storm charges
           10,100,000                                          
      environmental
           6,100,000                                          
      income taxes
           700,000                         4,800,000    7,700,000    7,000,000    8,900,000    7,500,000 
      other deferred charges
           13,100,000                                          
      total regulatory assets
           114,100,000                                          
      less: current portion of regulatory assets
           61,100,000                                          
      regulatory assets – noncurrent
           53,000,000                                          
      regulatory liabilities consist of the following
           2,024,000,000                                          
      rate adjustment mechanisms & other
           20,600,000                                          
      total regulatory liabilities
           57,800,000                                          
      less: current portion of regulatory liabilities
           24,500,000                                          
      regulatory liabilities – noncurrent
           33,300,000                                          
      fair value of marketable securities
           2,024,000,000                                          
      money market funds
           1,800,000                                          
      fixed income funds
           4,000,000                                          
      total marketable securities
           5,800,000                                          
      equity funds
           1,700,000                                          
      energy supply obligations
           2,024,000,000                                          
      current:
                                                     
      exchange gas obligation
           5,500,000                                          
      renewable energy portfolio standards
           3,100,000                                          
      total energy supply obligations
           8,600,000                                          
      net income
             7,425,000 1,400,000 4,200,000 24,100,000 6,725,000 500,000 4,900,000 21,500,000 5,400,000  2,700,000 18,900,000 13,600,000 300,000 3,100,000 15,200,000 11,400,000 2,300,000 4,000,000 26,500,000 11,000,000 2,800,000 3,600,000 15,600,000 11,200,000 2,300,000 3,100,000 12,400,000 4,225,000 3,500,000 2,500,000 10,900,000 4,250,000 1,700,000 1,700,000 13,600,000 9,400,000 1,600,000 1,100,000  
      yoy
             10.41% 180.00% -14.29% 12.09% 24.54% NaN% 81.48% 13.76% -60.29% NaN% -12.90% 24.34% 19.30% -86.96% -22.50% -42.64% 3.64% -17.86% 11.11% 69.87% -1.79% 21.74% 16.13% 25.81% 165.09% -34.29% 24.00% 13.76% -0.59% 105.88% 47.06% -19.85% -54.79% 6.25% 54.55%      
      qoq
             430.36% -66.67% -82.57% 258.36% 1245.00% -89.80% -77.21% 298.15% NaN% NaN% -85.71% 38.97% 4433.33% -90.32% -79.61% 33.33% 395.65% -42.50% -84.91% 140.91% 292.86% -22.22% -76.92% 39.29% 386.96% -25.81% -75.00% 193.49% 20.71% 40.00% -77.06% 156.47% 150.00% 0.00% -87.50% 44.68% 487.50% 45.45%   
      net income per common share
             462,500 90,000 250,000 1,510,000 420,000 30,000 300,000 1,350,000 355,000  180,000 1,260,000 312,500 20,000 210,000 1,020,000 550,000 150,000 270,000 1,780,000 372,500 190,000 240,000 1,060,000 317,500 160,000 230,000 880,000 302,500 250,000 180,000 780,000 305,000 120,000 120,000 980,000 275,000 110,000 80,000  
      weighted-average common shares outstanding –
              16,100,000 16,000,000 16,000,000  16,000,000 16,000,000 16,000,000  15,500,000 15,000,000 15,000,000  14,900,000 14,900,000 14,900,000  14,900,000 14,900,000 14,900,000   14,800,000 14,800,000  14,100,000 14,100,000 14,000,000  14,000,000 14,000,000 14,000,000  13,900,000 13,900,000 13,900,000  13,800,000 13,800,000 13,800,000 
      other income
               -100,000  475,000 600,000 600,000 700,000 1,200,000 1,000,000 1,100,000 1,300,000 1,200,000 1,100,000 1,400,000 1,500,000 1,200,000 1,000,000 1,300,000 -12,100,000 1,700,000 1,100,000 1,300,000 1,700,000   100,000  100,000 100,000 100,000  -700,000  100,000 100,000 100,000 100,000 100,000 100,000 
      benefit from income taxes
               700,000    100,000 7,400,000   700,000 6,500,000 1,450,000 400,000 700,000 4,700,000 2,550,000 900,000  8,200,000                     
      benefit for income taxes
                 1,750,000 -500,000   1,725,000 -300,000         1,100,000                      
      weighted-average common shares outstanding
                                  14,800,000                   
      dividends declared per share of common stock
                                 0.274 0.365 0.365 0.365 0.27 0.36 0.36 0.36 0.266 0.355 0.355 0.355 0.263 0.35 0.35 0.35 0.259 0.345 0.345 0.345 
      income tax benefit
                                   -200,000                600,000  
      earnings applicable to common shareholders
                                                    12,600,000 
      earnings per common share
                                                    910,000 
    Balance Sheets:
    Quarterly
    Annual
      Unit: USD2026-03-31 2025-12-31 2025-09-30 2025-06-30 2025-03-31 2024-12-31 2024-09-30 2024-06-30 2024-03-31 2023-12-31 2023-09-30 2023-06-30 2023-03-31 2022-12-31 2022-09-30 2022-06-30 2022-03-31 2021-09-30 2021-06-30 2021-03-31 2020-09-30 2020-06-30 2020-03-31 2019-09-30 2019-06-30 2019-03-31 2018-09-30 2018-06-30 2018-03-31 2017-09-30 2017-06-30 2017-03-31 2016-12-31 2016-09-30 2016-06-30 2016-03-31 2015-12-31 2015-09-30 2015-06-30 2015-03-31 2014-12-31 2014-09-30 2014-06-30 2014-03-31 2013-12-31 2013-09-30 2013-06-30 2012-12-31 2012-09-30 2012-06-30 2011-12-31 2011-09-30 2011-06-30 2010-12-31 2010-09-30 2010-06-30 2010-03-31 2009-12-31 2009-09-30 2009-06-30 2009-03-31 2008-12-31 2008-09-30 2008-06-30 2008-03-31 2007-12-31 2007-09-30 2007-06-30 2007-03-31 2006-12-31 2006-09-30 2006-06-30 2006-03-31 2005-12-31 2005-09-30 2005-06-30 2005-03-31 2004-12-31 2004-09-30 2004-06-30 2004-03-31 2003-12-31 
                                                                                        
        assets:
                                                                                        
        current assets:
                                                                                        
        cash and cash equivalents
      16,900,000 15,600,000 14,600,000 8,500,000 10,200,000 6,300,000 6,300,000 2,800,000 6,300,000 6,500,000 6,000,000 6,800,000 6,800,000 9,000,000 7,900,000 5,100,000 6,500,000 8,800,000 5,000,000 6,100,000 8,200,000 4,200,000 6,200,000 7,300,000 4,800,000 4,300,000 6,300,000 8,500,000 9,500,000 10,900,000 7,800,000 8,800,000 5,800,000 4,400,000 7,900,000 8,100,000 8,700,000 8,900,000 16,100,000 11,200,000 8,400,000 10,100,000 12,000,000 14,300,000 9,400,000                                      
        accounts receivable
      107,000,000 98,600,000 63,600,000 66,000,000 95,500,000 75,000,000 56,000,000 60,000,000 83,900,000 75,000,000 57,700,000 59,500,000 92,200,000 73,800,000 51,700,000 54,300,000 81,900,000 46,300,000 50,300,000 73,200,000 48,600,000 48,300,000 62,600,000 39,400,000 48,700,000 73,900,000 52,300,000 56,200,000 74,400,000 45,800,000 41,100,000 57,600,000 52,900,000 43,100,000 42,900,000 58,000,000 49,800,000 45,400,000 52,300,000 85,900,000 60,700,000 41,600,000 44,900,000 69,500,000 52,200,000 35,200,000 40,800,000 45,900,000 30,700,000 31,700,000 44,200,000 30,400,000 32,900,000 36,900,000  5,600,000 -6,800,000 6,200,000 12,500,000 8,800,000 -12,200,000 -6,400,000 1,700,000 2,400,000 -4,000,000 -2,400,000 -300,000 800,000 -5,900,000 1,085 935 513 -2,873 -5,512 -1,529 69 -3,715 -658 1,749 1,802 -1,698 2,052 
        accrued revenue
      78,200,000 87,000,000 64,700,000 56,800,000 60,500,000 77,400,000 65,400,000 65,900,000 72,200,000 63,400,000 57,300,000 60,400,000 71,600,000 72,800,000 46,900,000 45,600,000 56,300,000 38,600,000 34,600,000 34,700,000 39,100,000 34,900,000 38,600,000 35,300,000 32,100,000 40,200,000 36,000,000 29,700,000 45,100,000 39,200,000 36,600,000 41,300,000 49,500,000 35,500,000 31,900,000 42,100,000 38,400,000 28,800,000 28,600,000 64,200,000 48,500,000 31,400,000 33,400,000 49,600,000 56,600,000 40,200,000 38,300,000 58,100,000 34,600,000 30,700,000 56,600,000 35,200,000 26,000,000 46,700,000 35,700,000 21,500,000 16,600,000 12,900,000 22,900,000 25,900,000 9,400,000 -10,300,000 -2,000,000 -1,500,000 -1,300,000 1,100,000 4,300,000 4,800,000 1,800,000 -4,861 -1,648 -743 1,586 849 4,639 3,176 3,626 275 4,422 3,492 2,757 -6,795 
        exchange gas receivable
      1,400,000 9,800,000 15,100,000 9,100,000 1,600,000 6,400,000 9,300,000 5,800,000 2,200,000 9,400,000 14,000,000 9,400,000 4,700,000 18,000,000 25,100,000 13,400,000 700,000 10,500,000 5,200,000 1,200,000 6,500,000 4,200,000 2,200,000 8,600,000 5,300,000 400,000 10,100,000 5,500,000 200,000 9,500,000 5,900,000 2,100,000 8,300,000 9,800,000 8,000,000 6,800,000 11,100,000 10,600,000 7,200,000 4,000,000 15,000,000 14,500,000 8,300,000 1,300,000 10,800,000 12,800,000 7,600,000                                    
        gas inventory
      600,000 1,300,000 1,300,000 700,000 400,000 1,100,000 1,100,000 400,000 300,000 1,000,000 1,200,000 1,000,000 800,000 1,800,000 1,700,000 1,000,000 500,000 900,000 600,000 400,000 600,000 500,000 400,000 800,000 700,000 500,000  600,000 400,000 700,000 500,000 300,000 600,000 600,000 400,000 400,000 800,000 600,000 500,000 400,000 1,100,000 1,000,000 800,000 600,000 1,200,000 1,200,000 800,000 10,500,000 12,300,000 9,100,000 14,800,000 15,600,000 8,300,000 10,600,000 15,900,000 3,200,000 7,700,000 17,300,000 -32,300,000 -32,300,000                       
        materials and supplies
      16,200,000 15,400,000 14,800,000 15,900,000 16,100,000 14,200,000 13,800,000 14,200,000 14,000,000 13,500,000 12,600,000 12,900,000 12,400,000 11,400,000 10,100,000 9,700,000 9,400,000 8,600,000 8,600,000 9,200,000 8,500,000 9,200,000 9,200,000 7,700,000 7,500,000 7,800,000 7,200,000 7,500,000 7,800,000 7,300,000        6,800,000 6,700,000 5,900,000  6,600,000 6,100,000 5,100,000  5,300,000 5,400,000  3,600,000 4,100,000  3,800,000 3,900,000  3,300,000                -554 185 1,075 -595 -629 123 1,128 -219 -658 -186 677 -538 
        prepayments and other
      16,600,000 12,400,000 9,400,000 13,100,000 11,200,000 8,400,000 6,900,000 10,900,000 10,500,000 8,300,000 7,600,000 11,300,000 9,400,000 8,000,000 7,200,000 10,000,000 7,800,000 7,300,000 9,900,000 7,900,000 5,700,000 8,300,000 6,600,000 5,400,000 8,300,000 6,800,000 8,700,000 8,900,000 7,100,000 6,800,000 15,200,000 16,000,000 14,500,000 12,900,000 14,600,000 12,700,000 12,400,000 5,400,000 7,300,000 5,900,000 5,200,000 5,100,000 6,900,000 5,200,000 4,800,000 4,500,000 5,600,000 4,200,000 4,300,000 6,000,000 4,500,000 4,500,000 5,300,000 3,600,000 3,000,000                419 -289 316 159 405 -346 270 4,375 914 -585 3,014 -4,411 
        total current assets
      236,900,000 240,100,000 183,500,000 170,100,000 195,500,000 188,800,000 162,600,000 160,000,000 189,400,000 177,100,000 156,400,000 161,300,000 197,900,000 194,800,000 150,600,000 139,100,000 163,100,000 121,000,000 114,200,000 132,700,000 117,300,000 109,600,000 125,800,000 107,400,000 107,400,000 133,900,000 120,600,000 118,100,000 144,500,000 122,000,000 108,000,000 126,100,000 131,600,000 107,600,000 105,700,000 128,100,000 125,900,000 119,000,000 133,900,000 180,100,000 145,200,000 112,400,000 113,900,000 145,600,000 140,000,000 111,500,000 105,600,000 132,600,000 95,000,000 88,400,000 131,200,000 97,400,000 82,200,000 117,100,000 93,100,000                            
        utility plant:
                                                                                        
        electric
      758,400,000 752,200,000 734,800,000 728,200,000 705,800,000 699,400,000 670,200,000 663,200,000 659,800,000 654,900,000 634,000,000 638,400,000 629,900,000 627,500,000 612,700,000 610,100,000 606,700,000 581,000,000 578,600,000 576,800,000 545,900,000 541,700,000 538,400,000 514,800,000 511,600,000 511,300,000 485,600,000 479,700,000 478,800,000 454,600,000 442,000,000 440,900,000 437,900,000 424,000,000 421,200,000 409,900,000 408,400,000 398,400,000 396,400,000 393,700,000 390,600,000 382,900,000 379,100,000 377,300,000 375,600,000 361,300,000 359,100,000 356,900,000 348,200,000 345,900,000 333,300,000 326,600,000 326,500,000 321,500,000 313,500,000                            
        gas
      1,440,300,000 1,413,000,000 1,294,100,000 1,285,300,000 1,273,800,000 1,189,900,000 1,140,400,000 1,131,600,000 1,129,600,000 1,117,600,000 1,063,900,000 1,060,900,000 1,055,000,000 1,043,600,000 995,700,000 988,900,000 986,300,000 932,800,000 923,600,000 922,400,000 876,800,000 870,500,000 869,700,000 783,200,000 779,400,000 778,600,000 712,700,000 709,800,000 706,700,000 646,700,000 643,200,000 642,000,000 629,500,000 597,700,000 589,100,000 586,800,000 576,800,000 540,200,000 532,100,000 529,700,000 522,900,000 488,900,000 483,900,000 483,000,000 477,300,000 437,300,000 431,600,000 424,400,000 398,400,000 393,400,000 382,300,000 363,900,000 366,700,000 360,100,000 348,500,000                            
        common
      75,900,000 75,300,000 74,200,000 72,300,000 69,200,000 69,000,000 67,700,000 67,800,000 64,900,000 70,000,000 68,900,000 68,900,000 68,900,000 67,600,000 66,700,000 66,700,000 66,600,000 64,800,000 64,600,000 64,500,000 63,300,000 62,800,000 62,800,000 61,600,000 61,200,000 61,100,000 82,100,000 69,500,000 69,100,000 36,000,000 35,400,000 35,900,000 35,800,000 35,700,000 35,600,000 35,800,000 35,500,000 35,400,000 35,000,000 34,600,000 32,700,000 32,400,000 32,300,000 31,600,000 31,600,000 31,500,000 31,500,000 30,900,000 30,600,000 30,600,000 29,800,000 30,400,000 30,400,000 30,200,000 30,400,000                            
        construction work in progress
      92,600,000 101,700,000 121,600,000 89,500,000 92,500,000 92,900,000 136,300,000 92,200,000 68,500,000 65,300,000 107,600,000 64,200,000 53,800,000 52,600,000 81,900,000 56,200,000 36,500,000 84,800,000 60,600,000 38,300,000 101,000,000 68,900,000 43,300,000 72,900,000 44,900,000 26,100,000 68,400,000 51,000,000 32,100,000 113,000,000 92,700,000 68,600,000 70,200,000 89,600,000 69,600,000 56,900,000 59,900,000 77,600,000 57,400,000 39,400,000 42,600,000 54,200,000 34,300,000 21,300,000 24,600,000 58,200,000 40,400,000 19,400,000 35,800,000 23,100,000 28,300,000 41,400,000 21,200,000 16,600,000 18,900,000                            
        utility plant
      2,367,200,000 2,342,200,000 2,224,700,000 2,175,300,000 2,141,300,000 2,051,200,000 2,014,600,000 1,954,800,000 1,922,800,000 1,907,800,000 1,874,400,000 1,832,400,000 1,807,600,000 1,791,300,000 1,757,000,000 1,721,900,000  1,663,400,000 1,627,400,000  1,587,000,000 1,543,900,000  1,432,500,000 1,397,100,000        1,173,400,000    1,080,600,000    988,800,000    909,100,000   831,600,000   773,700,000   728,400,000                             
        less: accumulated depreciation
      554,400,000 543,700,000 541,800,000 530,900,000 522,400,000 511,600,000 512,200,000 500,000,000 493,000,000 486,900,000 484,300,000 474,600,000 466,300,000 459,600,000 453,200,000 442,800,000 436,200,000 426,100,000 417,600,000 409,700,000 401,700,000 396,300,000 389,100,000 348,600,000 343,600,000 339,300,000 326,500,000 320,200,000 314,300,000 303,600,000 300,600,000 296,500,000 290,000,000 286,000,000 280,900,000 276,300,000 271,700,000 269,200,000 263,900,000 259,200,000 255,100,000 252,400,000 247,900,000 246,400,000 243,500,000 241,300,000 237,200,000 230,400,000 277,900,000 273,000,000 263,000,000 262,500,000 260,600,000 251,900,000 247,700,000                            
        net utility plant
      1,812,800,000 1,798,500,000 1,682,900,000 1,644,400,000 1,618,900,000 1,539,600,000 1,502,400,000 1,454,800,000 1,429,800,000 1,420,900,000 1,390,100,000 1,357,800,000 1,341,300,000 1,331,700,000 1,303,800,000 1,279,100,000 1,259,900,000 1,237,300,000 1,209,800,000 1,192,300,000 1,185,300,000 1,147,600,000 1,125,100,000 1,083,900,000 1,053,500,000 1,037,800,000 1,022,300,000 989,800,000 972,400,000 946,700,000 912,700,000 890,900,000 883,400,000 861,000,000 834,600,000 813,100,000 808,900,000 782,400,000 757,000,000 738,200,000 733,700,000 706,000,000 681,700,000 666,800,000 665,600,000 647,000,000 625,400,000 601,200,000 535,100,000 520,000,000 510,700,000 499,800,000 484,200,000 476,500,000 463,600,000                            
        other noncurrent assets:
                                                                                        
        regulatory assets
      39,100,000 38,800,000 45,100,000 46,600,000 47,200,000 41,900,000 49,500,000 53,000,000 52,100,000 53,100,000 50,900,000 51,500,000 51,600,000 47,800,000 105,500,000 106,600,000 108,100,000 132,400,000 131,100,000 128,700,000 104,400,000 104,900,000 105,300,000 98,700,000 97,300,000 97,900,000 111,600,000 110,700,000 111,200,000 102,000,000 102,900,000 103,500,000 104,100,000 96,500,000 98,100,000 98,200,000 99,600,000 102,800,000 104,300,000 106,200,000 107,600,000 85,300,000 88,100,000 96,500,000 100,100,000 120,900,000 125,900,000 136,000,000 136,900,000 139,800,000 139,800,000 130,900,000 136,100,000 143,000,000 142,000,000                            
        operating lease right of use assets
      6,500,000 7,000,000 6,800,000 5,700,000 6,200,000 6,700,000 4,600,000 5,100,000 5,600,000 5,600,000 5,500,000 5,200,000 5,700,000 4,300,000 4,600,000 4,400,000 4,800,000 5,100,000 4,900,000 5,400,000 5,600,000 4,500,000 4,900,000 4,200,000 3,600,000 3,900,000                                                         
        goodwill
      4,300,000 4,300,000 1,600,000 1,600,000                                                                               
        other assets
      56,200,000 45,500,000 24,800,000 24,300,000 22,900,000 17,500,000 18,000,000 22,100,000 21,000,000 13,700,000 17,300,000 19,500,000 18,200,000 11,800,000 14,400,000 17,900,000 16,400,000 13,200,000 17,100,000 17,900,000 11,300,000 17,900,000 17,300,000 15,500,000 17,500,000 16,700,000 10,000,000 16,000,000 16,200,000 9,200,000 14,100,000 13,900,000 9,100,000 7,300,000 13,300,000 13,500,000 12,000,000 13,800,000 16,200,000 16,300,000 13,700,000 12,800,000 16,900,000 19,100,000 14,900,000                                      
        total other noncurrent assets
      106,100,000 95,600,000 78,300,000 78,200,000 76,300,000 66,100,000 72,100,000 80,200,000 78,700,000 72,400,000 73,700,000 76,200,000 75,500,000 63,900,000 124,500,000 128,900,000 129,300,000 150,700,000 153,100,000 152,000,000 121,300,000 127,300,000 127,500,000 118,400,000 118,400,000 118,500,000 121,600,000 126,700,000 127,400,000 111,200,000 117,000,000 117,400,000 113,200,000 103,800,000 111,400,000 111,700,000 111,600,000 116,600,000 120,500,000 122,500,000 121,300,000 98,100,000 105,000,000 115,600,000 115,000,000                                      
        total assets
      2,155,800,000 2,134,200,000 1,944,700,000 1,892,700,000 1,890,700,000 1,794,500,000 1,737,100,000 1,695,000,000 1,697,900,000 1,670,400,000 1,620,200,000 1,595,300,000 1,614,700,000 1,590,400,000 1,578,900,000 1,547,100,000 1,552,300,000 1,509,000,000 1,477,100,000 1,477,000,000 1,423,900,000 1,384,500,000 1,378,400,000 1,309,700,000 1,279,300,000 1,290,200,000 1,264,500,000 1,234,600,000 1,244,300,000 1,179,900,000 1,137,700,000 1,134,400,000 1,128,200,000 1,072,400,000 1,051,700,000 1,052,900,000 1,046,400,000 1,018,000,000 1,011,400,000 1,040,800,000 1,000,200,000 916,500,000 900,600,000 928,000,000 920,600,000 895,200,000 874,200,000 886,600,000 784,000,000 768,300,000 800,200,000 748,700,000 727,600,000 759,600,000 725,000,000                            
        liabilities and capitalization:
                                                                                        
        current liabilities:
                                                                                        
        accounts payable
      47,200,000 62,900,000 42,800,000 41,100,000 42,900,000 49,700,000 36,200,000 37,200,000 37,900,000 47,700,000 35,600,000 36,700,000 46,300,000 68,600,000 35,200,000 34,300,000 39,000,000 29,500,000 32,600,000 28,700,000 25,100,000 24,700,000 26,500,000 22,900,000 21,900,000 33,000,000 27,400,000 24,700,000 30,100,000 24,100,000 23,000,000 28,100,000 32,400,000 23,100,000 21,400,000 27,000,000 33,300,000 21,200,000 19,000,000 34,800,000 44,200,000 19,300,000 20,500,000 31,800,000 38,100,000 21,500,000 21,700,000 30,900,000 17,100,000 15,900,000 26,400,000 16,000,000 15,800,000 26,500,000 16,000,000 -8,400,000 -7,300,000 -3,400,000 -17,700,000 -17,200,000 -6,400,000 11,400,000 400,000 600,000 -2,000,000 -2,200,000 -4,800,000 -4,700,000 -1,900,000 -787 -4,515 -895 -5,908 4,351 -3,082 -2,355 -1,025 1,225 -1,580 -608 1,132 803 
        short-term debt
      258,000,000 255,700,000 117,500,000 171,400,000 172,900,000 105,800,000 64,300,000 157,800,000 169,900,000 162,000,000 129,500,000 131,700,000 140,200,000 116,000,000 72,000,000 46,200,000 64,000,000 30,500,000 29,700,000 37,300,000 17,300,000 74,900,000 71,600,000 49,200,000 64,800,000 65,800,000 69,100,000 37,400,000 45,300,000 111,900,000 79,200,000 76,600,000 81,900,000 36,900,000 54,200,000 47,900,000 42,000,000 4,100,000  32,000,000 29,300,000 1,400,000 35,000,000 59,200,000 60,200,000 43,600,000 24,500,000 49,400,000 24,100,000 5,000,000 87,900,000 65,400,000 51,300,000 66,800,000 46,300,000                            
        long-term debt, current portion
      37,900,000 37,900,000 34,900,000 4,900,000 4,900,000 4,900,000 4,900,000 4,900,000 4,900,000 4,900,000 7,000,000 6,900,000 6,700,000 6,700,000 8,200,000 8,200,000 8,200,000 10,100,000 19,000,000 8,500,000 6,300,000 6,300,000 6,300,000 19,500,000 19,500,000 19,500,000 31,800,000 29,700,000 29,800,000 29,800,000 29,900,000 30,000,000 16,800,000 17,000,000 17,200,000 17,100,000 17,400,000 4,100,000 4,100,000 4,000,000 4,000,000 2,500,000 2,500,000 2,500,000 2,500,000 600,000 600,000 500,000 500,000 500,000 500,000 500,000 500,000 500,000 500,000                            
        regulatory liabilities
      23,400,000 16,700,000 18,400,000 21,000,000 23,800,000 17,200,000 22,400,000 24,500,000 17,900,000 13,500,000 16,900,000 18,400,000 17,000,000 15,000,000 20,800,000 25,900,000 15,600,000 13,100,000 17,100,000 14,700,000 10,600,000 12,600,000 10,500,000 14,400,000 18,500,000 15,000,000 12,200,000 14,200,000 10,900,000 15,000,000 16,600,000 12,800,000 10,400,000 13,200,000 15,900,000 18,800,000 15,600,000 28,100,000 31,200,000 39,400,000 8,700,000 13,000,000 13,000,000 13,100,000 9,700,000 11,400,000 13,300,000            31,300,000 31,300,000                       
        energy supply obligations
      3,500,000 11,600,000 17,000,000 11,100,000 6,200,000 10,000,000 12,800,000 8,600,000 7,000,000 15,000,000 18,700,000 13,900,000 10,600,000 24,100,000 29,800,000 16,600,000 6,900,000 16,100,000 9,900,000 7,700,000 12,100,000 8,400,000 7,900,000 12,500,000 9,200,000 4,600,000 15,000,000 9,400,000 7,800,000 12,900,000 10,300,000 9,000,000 12,000,000 13,200,000 12,800,000 13,900,000 14,600,000 15,800,000 13,800,000 12,600,000 22,100,000 18,100,000 12,300,000 6,100,000 14,400,000   13,800,000                                   
        interest payable
      8,200,000 9,400,000 7,900,000 8,600,000 7,900,000 8,400,000 7,400,000 6,000,000 7,200,000  6,500,000 5,200,000 6,100,000  6,500,000 4,800,000 6,400,000 6,700,000 4,900,000 6,800,000 7,200,000 4,200,000 7,200,000 7,100,000 4,000,000 7,000,000  4,100,000 6,900,000 6,000,000 3,900,000 6,000,000  6,300,000 3,500,000 6,100,000  6,300,000 3,500,000 6,300,000 3,500,000 5,400,000 3,100,000 5,400,000 3,100,000 5,400,000 3,100,000                        1,111  1,088 25 867  867 -28 839 -28 664 45 
        environmental obligations
      800,000 800,000 800,000 700,000 700,000 700,000 800,000 700,000 700,000 600,000 600,000 600,000 600,000 600,000 600,000 600,000 500,000 700,000 400,000 300,000 300,000 300,000 300,000     600,000 600,000 500,000 500,000 500,000 400,000 300,000 300,000 700,000 1,300,000 5,000,000 3,400,000 3,400,000 3,500,000 5,300,000 6,400,000 1,400,000 13,800,000 13,800,000 13,800,000 13,800,000 14,500,000 14,500,000 14,500,000 14,400,000 14,500,000 14,500,000 14,200,000                            
        operating lease obligations
      2,000,000 2,100,000 1,900,000 1,700,000 1,800,000 1,800,000    1,900,000                                                                         
        taxes payable
      11,200,000  3,200,000 6,000,000 10,400,000   8,000,000 8,900,000 1,900,000  2,300,000                       400,000  2,400,000 4,900,000 9,100,000         700,000 500,000 100,000 1,000,000 600,000 400,000          300,000 800,000 2,900,000  2,600,000 1,500,000 1,200,000 888             
        other current liabilities
      23,700,000 28,700,000 30,200,000 27,000,000 23,500,000 30,200,000 30,400,000 26,600,000 22,200,000 29,800,000 28,600,000 22,300,000 26,000,000 29,100,000 20,500,000 18,400,000 17,100,000 19,900,000 19,700,000 18,900,000 19,300,000 17,900,000 16,800,000 18,800,000 18,100,000 19,900,000 21,900,000 12,200,000 11,800,000 13,000,000 11,500,000 11,000,000 20,000,000 13,200,000 10,200,000 11,400,000 14,900,000 11,700,000 10,400,000 7,900,000 11,000,000 11,000,000 9,800,000 8,800,000 10,000,000 10,500,000 9,700,000 16,700,000 21,400,000 20,200,000 17,500,000 22,500,000 17,300,000 16,100,000 24,200,000                -196 -460 -923 1,311 948 616 336 1,353 1,243 460 313 -4,808 
        total current liabilities
      415,900,000 425,800,000 274,600,000 293,500,000 295,000,000 228,700,000 179,200,000 274,300,000 276,600,000 277,300,000 243,400,000 238,000,000 253,500,000 260,100,000 193,600,000 155,000,000 157,700,000 126,600,000 133,300,000 122,900,000 98,200,000 149,300,000 147,100,000 144,400,000 156,000,000 164,800,000 180,500,000 135,400,000 146,300,000 216,300,000 177,900,000 177,000,000 176,900,000 126,300,000 139,000,000 146,000,000 144,600,000 101,200,000 94,500,000 140,400,000 129,400,000 76,000,000 102,600,000 131,700,000 144,700,000 115,500,000 90,600,000 125,400,000 77,000,000 54,400,000 154,400,000 126,800,000 100,800,000 126,900,000 110,000,000                            
        noncurrent liabilities:
                                                                                        
        deferred income taxes
      198,300,000 196,700,000 188,200,000 187,200,000 184,600,000 186,100,000 176,600,000 178,600,000 179,100,000 176,100,000 173,700,000 171,300,000 171,100,000 163,400,000 136,100,000 136,400,000 135,000,000 115,700,000 115,400,000 115,400,000 109,400,000 109,000,000 108,700,000 108,300,000 104,100,000 103,800,000 86,400,000 88,100,000 87,000,000 109,200,000 106,800,000 106,000,000 97,900,000 99,600,000 95,600,000 93,100,000 4,700,000 12,500,000 15,200,000 2,600,000 3,100,000 2,100,000 1,500,000 3,400,000 6,700,000    51,700,000 51,800,000 46,300,000 46,700,000 48,100,000 43,800,000 37,200,000                            
        cost of removal obligations
      156,500,000 153,000,000 151,400,000 147,400,000 143,900,000 139,200,000 139,300,000 134,900,000 130,600,000 126,300,000 125,800,000 123,200,000 120,000,000 116,100,000 115,400,000 112,400,000 109,800,000 108,200,000 105,100,000 102,500,000 107,100,000 102,600,000 98,800,000 98,400,000 94,000,000 93,700,000 91,200,000 87,800,000 86,600,000 84,800,000 82,300,000 79,700,000 77,000,000 77,400,000 74,900,000 72,300,000 70,100,000 69,900,000 68,100,000 65,700,000 63,800,000 63,200,000 60,800,000 59,200,000 57,300,000 56,700,000 54,700,000 51,400,000                                   
        retirement benefit obligations
      33,300,000 32,900,000 26,000,000 26,300,000 25,800,000 25,500,000 42,500,000 46,400,000 46,000,000 45,600,000 41,300,000 44,300,000 46,800,000 46,800,000 135,200,000 135,900,000 136,300,000 166,200,000 165,100,000 164,800,000 145,000,000 147,500,000 145,400,000 120,800,000 123,300,000 122,900,000 142,400,000 154,700,000 151,600,000 155,000,000 153,300,000 151,500,000 149,000,000 127,800,000 128,300,000 126,800,000 124,400,000 122,000,000 123,500,000 121,400,000 118,600,000 81,800,000 80,800,000 79,100,000 77,300,000 107,900,000 110,600,000 103,700,000 88,900,000 91,100,000 91,200,000 74,100,000 72,100,000 74,000,000 67,200,000                            
        other noncurrent liabilities
      7,500,000 7,300,000 6,600,000 6,100,000 5,900,000 5,300,000 8,400,000 8,300,000 8,800,000 4,600,000 8,400,000 8,300,000 8,600,000 6,600,000 6,600,000 6,900,000 7,300,000 6,800,000 7,200,000 7,000,000 7,800,000 7,300,000 7,200,000 10,200,000 8,900,000 10,700,000 6,600,000 5,600,000 5,700,000 4,600,000 4,900,000 4,900,000 5,100,000 3,800,000 4,500,000 3,500,000 3,600,000 3,500,000 3,500,000 1,900,000 1,900,000 4,100,000 5,600,000 4,000,000 1,800,000 2,200,000 2,200,000 2,400,000 7,900,000 8,400,000 8,100,000 9,400,000 7,400,000 8,500,000 8,800,000                            
        total noncurrent liabilities
      472,500,000 466,200,000 437,300,000 430,600,000 424,400,000 414,900,000 417,100,000 405,500,000 402,600,000 394,700,000 388,000,000 386,700,000 386,800,000 373,600,000 433,400,000 432,700,000 432,700,000 441,500,000 437,700,000 435,000,000 415,900,000 413,100,000 407,100,000 384,400,000 377,200,000 378,500,000 377,900,000 388,900,000 386,400,000 361,700,000 355,900,000 352,100,000 341,400,000 324,000,000 319,400,000 311,400,000 310,900,000 310,700,000 307,800,000 288,400,000 268,600,000 245,900,000 242,600,000 237,600,000 225,900,000 238,700,000 238,600,000 213,300,000 114,900,000 117,800,000 118,000,000 104,000,000 102,300,000 109,600,000 103,800,000                            
        capitalization:
                                                                                        
        long-term debt, less current portion
      631,400,000 632,600,000 635,600,000 635,800,000 637,200,000 638,400,000 638,400,000 506,400,000 507,900,000 509,100,000 509,000,000 486,200,000 488,000,000 489,100,000 493,100,000 495,100,000 496,600,000 501,300,000 505,300,000 515,800,000 529,000,000 436,400,000 436,300,000 410,900,000 373,100,000 373,000,000 361,100,000 363,100,000 363,000,000 303,600,000 303,500,000 303,500,000 316,800,000 335,000,000 305,200,000 305,400,000 308,100,000 328,400,000 328,600,000 328,700,000 328,900,000 326,700,000 284,600,000 284,700,000 284,800,000 286,900,000 287,000,000 287,300,000 287,500,000 287,600,000 287,800,000 288,000,000 288,100,000 288,300,000 288,500,000                            
        stockholders’ equity:
                                                                                        
        common equity
      419,900,000 418,200,000 416,700,000 344,600,000 342,600,000 341,200,000 339,800,000 339,300,000 338,700,000 337,600,000 337,000,000 336,500,000 336,100,000 334,900,000 334,400,000 334,100,000 333,700,000 331,600,000 286,800,000 286,300,000 284,800,000 284,400,000 284,000,000 281,700,000 281,300,000 280,700,000 278,300,000 277,900,000 277,400,000 243,400,000 242,700,000 242,100,000 240,700,000 239,900,000 239,400,000 238,900,000 237,500,000 236,800,000 236,400,000 236,000,000 234,700,000 233,900,000 233,600,000 233,100,000 232,100,000                                      
        retained earnings
      215,900,000 191,200,000 180,300,000 188,000,000 191,300,000 171,100,000 162,400,000 169,300,000 171,900,000 151,500,000 142,600,000 147,700,000 150,100,000 132,500,000 124,200,000 130,000,000 131,400,000 107,800,000 113,800,000 116,800,000 95,800,000 101,100,000 103,700,000 88,100,000 91,500,000 93,000,000 66,500,000 69,100,000 71,000,000 54,700,000 57,500,000 59,500,000 52,200,000 47,000,000 48,500,000 51,000,000 45,100,000 40,700,000 43,900,000 47,100,000 38,400,000 33,800,000 37,000,000 40,700,000 32,900,000                                      
        total common stock equity
      635,800,000 609,400,000 597,000,000 532,600,000 533,900,000 512,300,000 502,200,000 508,600,000 510,600,000 489,100,000 479,600,000 484,200,000 486,200,000 467,400,000 458,600,000 464,100,000 465,100,000 439,400,000 400,600,000 403,100,000 380,600,000 385,500,000 387,700,000 369,800,000 372,800,000 373,700,000 344,800,000 347,000,000 348,400,000 298,100,000 300,200,000 301,600,000 292,900,000 286,900,000 287,900,000 289,900,000 282,600,000 277,500,000 280,300,000 283,100,000 273,100,000 267,700,000 270,600,000 273,800,000 265,000,000                                      
        preferred stock
      200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 200,000 2,000,000 2,000,000 2,000,000 2,000,000 2,000,000 2,000,000 2,000,000                            
        total stockholders’ equity
      636,000,000 609,600,000 597,200,000 532,800,000 534,100,000 512,500,000 502,400,000 508,800,000 510,800,000 489,300,000 479,800,000 484,400,000 486,400,000 467,600,000 458,800,000 464,300,000 465,300,000 439,600,000 400,800,000 403,300,000 380,800,000 385,700,000 387,900,000 370,000,000 373,000,000 373,900,000 345,000,000 347,200,000 348,600,000 298,300,000 300,400,000 301,800,000 293,100,000 287,100,000 288,100,000 290,100,000 282,800,000 277,700,000 280,500,000 283,300,000 273,300,000 267,900,000                                         
        total capitalization
      1,267,400,000 1,242,200,000 1,232,800,000 1,168,600,000 1,171,300,000 1,150,900,000 1,140,800,000 1,015,200,000 1,018,700,000 998,400,000 988,800,000 970,600,000 974,400,000 956,700,000 951,900,000 959,400,000 961,900,000 940,900,000 906,100,000 919,100,000 909,800,000 822,100,000 824,200,000 780,900,000 746,100,000 746,900,000 706,100,000 710,300,000 711,600,000 601,900,000 603,900,000 605,300,000 609,900,000 622,100,000 593,300,000 595,500,000 590,900,000 606,100,000 609,100,000 612,000,000 602,200,000 594,600,000 555,400,000 558,700,000 550,000,000 541,000,000 545,000,000 547,900,000 540,400,000 544,300,000 481,500,000 471,200,000 476,400,000 479,300,000 474,000,000                            
        commitments and contingencies
                                                                                        
        total liabilities and capitalization
      2,155,800,000 2,134,200,000 1,944,700,000 1,892,700,000 1,890,700,000 1,794,500,000 1,737,100,000 1,695,000,000 1,697,900,000 1,670,400,000 1,620,200,000 1,595,300,000 1,614,700,000 1,590,400,000 1,578,900,000 1,547,100,000 1,552,300,000 1,509,000,000 1,477,100,000 1,477,000,000 1,423,900,000 1,384,500,000 1,378,400,000 1,309,700,000 1,279,300,000 1,290,200,000 1,264,500,000 1,234,600,000 1,244,300,000 1,179,900,000 1,137,700,000 1,134,400,000 1,128,200,000 1,072,400,000 1,051,700,000 1,052,900,000 1,046,400,000 1,018,000,000 1,011,400,000 1,040,800,000 1,000,200,000 916,500,000 900,600,000 928,000,000 920,600,000                                      
        december 31,
       2,025,000,000    2,024,000,000    2,023,000,000    2,022,000,000                   2,016,000,000    2,015,000,000    2,014,000,000    2,013,000,000   2,012,000,000   2,011,000,000   2,010,000,000                             
        refundable taxes
            3,800,000                 2,900,000    1,200,000  1,800,000 900,000                       7,500,000                    626   3,719 2,839 6,746 2,998 4,157 1,035 
        total utility plant
                      1,696,100,000   1,602,000,000   1,514,200,000   1,377,100,000 1,348,800,000 1,310,000,000 1,286,700,000 1,250,300,000 1,213,300,000 1,187,400,000  1,147,000,000 1,115,500,000 1,089,400,000  1,051,600,000 1,020,900,000 997,400,000  958,400,000 929,600,000 913,200,000  888,300,000 862,600,000  813,000,000 793,000,000  762,300,000 744,800,000  711,300,000                            
        taxes refundable
                          100,000             1,300,000                                                 
        capital lease obligations
                                3,100,000 3,100,000 3,100,000 3,100,000 3,000,000 3,000,000 3,000,000 3,100,000 3,100,000 3,100,000 3,100,000 12,100,000 9,500,000 8,200,000 7,500,000 6,500,000 5,600,000                                        
        material and supplies
                                              6,300,000    5,000,000   4,100,000   3,600,000   2,900,000                             
        dividends declared and payable
                                                   4,800,000 4,800,000                                    
        common stock equity:
                                                                                        
        cash
                                                   12,300,000 7,100,000 9,800,000 9,500,000 6,800,000 7,500,000 7,900,000 5,800,000 8,900,000 8,000,000                            
        noncurrent assets:
                                                                                        
        other noncurrent assets
                                                   15,800,000 17,300,000 16,800,000 17,000,000 20,100,000 18,500,000 20,600,000 25,100,000 23,000,000 26,300,000                            
        total noncurrent assets
                                                   136,700,000 143,200,000 152,800,000 153,900,000 159,900,000 158,300,000 151,500,000 161,200,000 166,000,000 168,300,000                            
        capitalization and liabilities:
                                                                                        
        common stock equity
                                                   253,900,000 257,800,000 260,400,000 250,900,000 254,700,000 191,700,000 181,200,000 186,300,000 189,000,000 183,500,000                            
        energy supply contract obligations
                                                   15,400,000 9,800,000  13,400,000 12,700,000 21,100,000 21,800,000 15,500,000 17,000,000 23,000,000                            
        current deferred income taxes
                                                   2,300,000 3,100,000 13,400,000                                   
        noncurrent deferred income taxes
                                                   55,400,000 54,400,000 38,700,000                                   
        total capitalization and liabilities
                                                   895,200,000 874,200,000 886,600,000 784,000,000 768,300,000 800,200,000 748,700,000 727,600,000 759,600,000 725,000,000                            
        accounts receivable – net of allowance for doubtful accounts of 2.6, 2.4 and 2.5
                                                            27,200,000                            
        operating activities:
                                                                                        
        net income
                                                             4,500,000 6,500,000 10,000,000 8,800,000 9,400,000 9,100,000 9,700,000 6,500,000 5,000,000 3,300,000 8,700,000 6,000,000 4,400,000 2,600,000 8,033 5,305 3,478 2,043 8,553 5,847 4,246 2,710 8,226 5,676 4,410 2,806 7,958 
        adjustments to reconcile net income to cash
                                                                                        
        provided by operating activities:
                                                                                        
        depreciation and amortization
                                                             14,200,000 7,100,000 27,400,000 19,300,000 12,700,000 6,300,000 19,100,000 14,300,000 9,700,000 5,200,000 17,800,000 13,400,000 8,900,000 4,500,000 16,069 11,972 8,520 4,179 19,123 15,309 10,302 5,226 18,830 13,821 9,157 4,764 18,756 
        deferred tax provision
                                                             -5,300,000 -5,200,000                    -1,772 3,166 -2,397 -1,081 -1,409 6,375 
        changes in current assets and liabilities:
                                                                                        
        all other current assets and liabilities
                                                             400,000 6,800,000 -3,600,000 -14,200,000 -4,000,000 2,500,000 4,600,000 800,000  2,600,000 500,000 1,700,000 500,000 2,400,000 -86             
        deferred regulatory and other charges
                                                             -5,100,000  -24,600,000 -14,000,000 -12,200,000                       
        other
                                                             -3,600,000 -1,100,000 1,600,000 -1,500,000 -2,100,000 -1,900,000 9,200,000 300,000 -100,000 400,000 2,300,000 3,200,000 3,100,000 1,900,000 -1,578 3,552 1,188 -346 1,196 2,857 -97 -503 -2,952 -2,111 933 -2,111 1,114 
        cash from operating activities
                                                             27,000,000 24,300,000 50,900,000 21,200,000 18,700,000 5,000,000 47,300,000 27,100,000 19,800,000 7,900,000 26,800,000 23,600,000 17,000,000 6,100,000 20,373 17,143 10,971 694 24,076 21,000 13,749 8,825 30,648 28,664 20,764 15,066 15,621 
        investing activities:
                                                                                        
        property, plant and equipment additions
                                                             -19,200,000 -10,300,000 -58,700,000 -43,000,000 -26,100,000 -18,000,000 -28,300,000 -20,600,000 -10,200,000 -4,500,000 -32,500,000 -25,900,000 -19,600,000 -9,600,000 -33,642 -24,653 -14,438 -5,626 -24,367 -16,680 -9,498 -4,444 -22,922 -17,074 -10,636 -4,367 -21,939 
        acquisition costs
                                                                -6,800,000                        
        cash (used in) investing activities
                                                             -19,200,000 -10,300,000 -65,600,000 -49,800,000 -26,100,000 -18,000,000 -238,200,000 -20,600,000 -10,200,000 -4,500,000 -32,500,000 -25,900,000 -19,600,000 -9,600,000  -24,653 -14,438 -5,626  -16,680 -9,498 -4,444  -17,074    
        financing activities:
                                                                                        
        repayment of short-term debt
                                                             -39,900,000           -13,000,000         -185 -1,400    -6,980  
        proceeds from issuance (repayment of) long-term debt
                                                             39,700,000                           
        net decrease in gas inventory financing
                                                             -1,600,000 -3,800,000                          
        dividends paid
                                                             -7,600,000 -3,800,000 -13,200,000 -9,400,000 -5,600,000 -2,800,000 -8,100,000 -6,100,000 -4,000,000 -2,000,000 -7,900,000 -6,000,000 -4,000,000 -2,000,000 -7,908 -5,916 -3,939 -1,966 -7,843 -5,877 -3,913 -1,953 -7,857 -5,887 -3,921 -1,957 -7,056 
        proceeds from issuance of common stock
                                                             500,000 200,000 56,400,000 56,200,000 56,200,000 5,400,000 37,400,000                     
        cash (used in) financing activities
                                                             -9,200,000 -12,900,000                  -3,792 -3,948       
        net decrease in cash
                                                             -1,400,000                        -375 -1,206  
        cash at beginning of period
                                                             7,700,000 7,700,000  11,500,000 11,500,000 11,500,000  4,600,000 4,600,000 4,600,000  4,600,000 4,600,000 4,600,000  3,207 3,207 3,207  3,032 3,032 3,032  3,766 3,766 3,766  
        cash at end of period
                                                             6,300,000 8,800,000  9,000,000 10,300,000 14,500,000  5,000,000 4,300,000 4,000,000  4,200,000 2,200,000 2,800,000  3,821 3,854 2,213  3,560 3,335 4,164  3,821 3,391 2,560  
        supplemental cash flow information:
                                                                                        
        interest paid
                                                             9,700,000 2,000,000 19,300,000 11,600,000 9,700,000 2,600,000 12,500,000 8,000,000 6,100,000 2,100,000 12,200,000 7,600,000 5,700,000 2,000,000 10,690 7,018 5,358 1,542 9,455 6,154 4,685 1,460 9,052 -5,910 -4,524 1,603 9,113 
        income taxes paid
                                                             1,000,000 1,000,000 -3,800,000 600,000 500,000  -500,000 500,000 500,000 200,000 5,300,000 3,300,000 3,300,000 1,800,000 3,101 2,653 1,893 803 4,544 3,544 1,693  990    -2,541 
        description
                                                                                        
        natural gas futures contracts
                                                                                        
        total
                                                                                        
        proceeds from (repayment of) short-term debt
                                                              -45,200,000 -9,600,000 -20,100,000 -43,500,000 13,600,000 55,300,000 2,900,000 -6,000,000 -2,100,000 -7,200,000    7,300    -6,975    3,265 -2,665 -3,600  -13,580 
        proceeds from issuance of long-term debt
                                                              40,000,000     90,000,000    20,000,000 20,000,000 20,000,000   15,000            
        net increase in cash
                                                              1,100,000 -3,800,000 -2,500,000  3,000,000 6,900,000 400,000    -400,000 -2,400,000  1,349 614 647 -994 175 528 303 1,132 -734 55   -3,394 
        balance sheet location
                                                                                        
        fair value
                                                              1,900,000                          
        amount of gain recognized in regulatory asset / liability for derivatives
                                                              -3,100,000                          
        adjustments to reconcile net income to cash from operating activities:
                                                                                        
        deferred taxes provision
                                                               7,100,000   -1,800,000 7,400,000                     
        acquisitions
                                                               -6,900,000    -209,900,000                     
        repayment of long-term debt
                                                               -400,000    -400,000 -200,000   -300,000 -100,000   -310 -230 -151 -75 -286 -213 -141 -70 -3,264  -3,130 -3,064 -3,244 
        net increase in gas inventory financing
                                                               -21,800,000    24,000,000                     
        cash from financing activities
                                                               10,900,000 26,100,000 6,200,000 16,000,000 197,800,000 -6,100,000 -9,900,000 -4,000,000 5,700,000 1,900,000 200,000 1,700,000 14,618 8,124 4,114 3,938 466    -8,460    2,924 
        cash at beginning of year
                                                               11,500,000    4,600,000    4,600,000    3,207    3,032    3,766    7,160 
        cash at end of year
                                                               7,700,000    11,500,000    4,600,000    4,556    3,207    3,032    3,766 
        supplemental information:
                                                                                        
        balance at january 1, 2007
                                                               63,500,000                         
        net income for 2007
                                                                                        
        dividends
                                                                                        
        shares issued under stock plans
                                                               800,000    300,000                     
        issuance of 38,303 common shares
                                                               1,000,000    1,000,000    1,000,000                 
        balance at december 31, 2007
                                                               65,300,000    65,300,000    64,500,000                 
        net income for 2008
                                                                                        
        issuance of 32,754 common shares
                                                               800,000    800,000                     
        issuance of 2,000,000 common shares
                                                               36,200,000    36,200,000                     
        balance at december 31, 2008
                                                               102,700,000    102,700,000                     
        net income for 2009
                                                                                        
        issuance of 43,615 common shares
                                                               900,000                         
        issuance of 2,970,000 common shares
                                                               55,500,000                         
        balance at december 31, 2009
                                                               159,500,000                         
        deferred taxes
                                                                5,100,000 -2,600,000   2,400,000 1,200,000 -200,000 -900,000 -2,500,000 -2,300,000 -500,000  -1,185 -964 -1,352  -2,642 -2,653       
        equity purchase price
                                                                160,000,000 160,000,000                       
        plus: working capital adjustment
                                                                49,200,000 49,200,000                       
        aggregate purchase price
                                                                209,200,000 209,200,000                       
        transaction and transition costs
                                                                14,400,000 13,000,000                       
        total cash purchase price
                                                                223,600,000 222,200,000                       
        allocation to:
                                                                                        
        book value of net utility plant
                                                                -197,000,000 -197,000,000                       
        cash acquired
                                                                -6,900,000 -6,900,000                       
        accounts receivable and other current assets
                                                                -21,700,000 -21,700,000                       
        regulatory and other noncurrent assets
                                                                -34,200,000 -32,800,000                       
        accounts payable and other current liabilities
                                                                20,000,000 20,000,000                       
        plant acquisition adjustment
                                                                -24,200,000 -24,200,000                       
        net (decrease) in cash
                                                                 -1,200,000    -300,000 -600,000    -1,800,000              
        declaration date
                                                                                        
        03/26/09
                                                                  5,000,000                      
        01/15/09
                                                                  2,000,000                      
        09/25/08
                                                                  10,000,000  10,000,000                    
        06/19/08
                                                                  8,000,000  8,000,000 8,000,000                   
        03/20/08
                                                                  5,000,000  5,000,000 5,000,000 5,000,000                  
        01/17/08
                                                                  2,000,000  2,000,000 2,000,000 2,000,000                  
        deferred restructuring charges
                                                                   2,600,000 2,400,000 1,700,000 1,000,000 3,500,000    1,129     -5,083 -2,805 -2,161 -5,900    -6,058 
        balance at january 1, 2006
                                                                   62,200,000                     
        net income for 2006
                                                                                        
        issuance of 40,365 common shares
                                                                   1,000,000    1,000,000    1,001             
        balance at december 31, 2006
                                                                   63,500,000    62,200,000    61,827             
        issuance of common stock
                                                                    700,000 500,000 200,000 1,500,000 1,300,000 500,000 300,000 1,001 757 513 245 1,031 806 546 299 947 718 481 244 17,628 
        retirement of preferred stock
                                                                        -100,000 -100,000  -243 -244 -243 -222 -11 -11 -11  -931  -27  -53 
        acquisition-related expenditures
                                                                    -3,300,000                    
        09/13/07
                                                                    11,000,000 11,000,000 11,000,000  11,000,000                
        06/21/07
                                                                    8,000,000 8,000,000 8,000,000  8,000,000 8,000,000               
        03/22/07
                                                                    5,000,000 5,000,000 5,000,000  5,000,000 5,000,000 5,000,000              
        01/18/07
                                                                    2,000,000 2,000,000 2,000,000  2,000,000 2,000,000 2,000,000              
        proceeds from (repayment of) long-term debt
                                                                     -200,000                   
        taxes payable /
                                                                       -1,600,000                 
        balance at january 1, 2005
                                                                       59,900,000                 
        net income for 2005
                                                                                        
        dividends on preferred shares
                                                                                        
        dividends on common shares
                                                                                        
        stock compensation plans
                                                                       100,000                 
        issuance of 38,003 common shares
                                                                       1,000,000    1,031    1,031         
        balance at december 31, 2005
                                                                       61,000,000    60,826    60,826         
        exercised stock options – 42,437 common shares
                                                                       1,000,000                 
        09/29/06
                                                                        11,000,000 11,000,000 11,000,000  11            
        06/22/06
                                                                        8,000,000 8,000,000 8,000,000            
        03/23/06
                                                                        5,000,000 5,000,000 5,000,000           
        01/12/06
                                                                        2,000,000 2,000,000 2,000,000           
        proceeds from (repayment) of short-term debt
                                                                         -16,500,000   -1,125 7,950           
        proceeds from short-term debt
                                                                          3,700,000              
        deferred tax benefit
                                                                           481    -240         
        cash from investing activities
                                                                           -33,642    -24,367    -22,922  -10,636 -4,367 -21,939 
        issuance of long-term debt
                                                                           15,000    15,000        10,000 
        repayment of capital lease obligations
                                                                           -222 -118 -16 -69 -450 -347 -244 -125 -620  -306 -148 -771 
        balance at january 1, 2004
                                                                           58,848             
        net income for 2004
                                                                                        
        issuance of 35,310 common shares
                                                                           947    947    947     
        balance at december 31, 2004
                                                                           59,795    59,795    59,795     
        cash flow from operating activities:
                                                                                        
        taxes refundable / payable
                                                                            1,586 921 2,195  2,700 3,261       
        refundable customer deposits
                                                                            151 51 58 486 393 212 119 116    93 
        deferred restructuring and other charges
                                                                            210 -534 -444 -6,256         
        cash flows from investing activities:
                                                                                        
        cash flows from financing activities:
                                                                                        
        09/23/05
                                                                            11 11 11  11        
        06/17/05
                                                                                   
        03/24/05
                                                                                  
        01/13/05
                                                                                  
        issuance (repayment) of short-term debt
                                                                              6,025  1,850        
        supplemental schedule of noncash activities:
                                                                                        
        capital leases incurred
                                                                               439    246 246   109 
        balance at january 1, 2003
                                                                               41,220         
        net income for 2003
                                                                                        
        common stock offering—717,600 shares
                                                                               16,911    16,911    16,911 
        issuance of 28,714 common shares
                                                                               717    717    717 
        balance at december 31, 2003
                                                                               58,848    58,848    58,848 
        09/24/04
                                                                                11 11 11  11    
        06/24/04
                                                                                   
        03/31/04
                                                                                  
        01/15/04
                                                                                  
        cash (used in financing) activities
                                                                                  -3,249  -11,535    
        income taxes refunded
                                                                                  478    1,333  
        gain on sale of investments
                                                                                        
        proceeds from the sale of investments
                                                                                        
        balance at january 1, 2002
                                                                                   41,220     
        net income for 2002
                                                                                        
        redemption premium on preferred shares
                                                                                        
        balance at december 31, 2002
                                                                                   41,220    41,220 
        (repayment of) long-term debt
                                                                                    -3,196    
        (retirement of) preferred stock
                                                                                    -27    
        (repayment of) capital lease obligations
                                                                                    -478    
        income taxes (paid) refunded
                                                                                    -869 -368   
        09/26/03
                                                                                    11 11 11  
        06/26/03
                                                                                     
        03/21/03
                                                                                     
        01/16/03
                                                                                     
        cash from (used in financing) activities
                                                                                     -10,503 -11,905  
        (gain) loss on sale of investments
                                                                                        
        proceeds from the sale of electric generation assets
                                                                                        
        balance at january 1, 2001
                                                                                       40,991 
        net income after extraordinary item for 2001
                                                                                        
        issuance of 11,279 common shares
                                                                                       287 
        re-acquired and retired common shares
                                                                                       -58 
        balance at december 31, 2001
                                                                                       41,220 
      Cashflow Statements:
      Quarterly
      Annual
        Unit: USD2025-12-31 2025-09-30 2025-06-30 2025-03-31 2024-12-31 2024-09-30 2024-06-30 2024-03-31 2023-12-31 2023-09-30 2023-06-30 2023-03-31 2022-12-31 2022-09-30 2022-06-30 2022-03-31 2021-12-31 2021-09-30 2021-06-30 2021-03-31 2020-12-31 2020-09-30 2020-06-30 2020-03-31 2019-12-31 2019-09-30 2019-06-30 2019-03-31 2018-09-30 2018-06-30 2018-03-31 2017-09-30 2017-06-30 2017-03-31 2016-12-31 2016-09-30 2016-06-30 2016-03-31 2015-12-31 2015-09-30 2015-06-30 2015-03-31 2014-12-31 2014-09-30 2014-06-30 2014-03-31 2013-12-31 2013-09-30 2013-06-30 2013-03-31 2012-12-31 2012-09-30 2012-06-30 2012-03-31 2011-12-31 2011-09-30 2011-06-30 2011-03-31 2010-12-31 2010-09-30 2010-06-30 2010-03-31 2009-12-31 2009-09-30 2009-06-30 2009-03-31 2008-12-31 2008-09-30 2008-06-30 2008-03-31 2007-12-31 2007-09-30 2007-06-30 2007-03-31 2006-12-31 2006-09-30 2006-06-30 2006-03-31 2005-12-31 2005-09-30 2005-06-30 2005-03-31 2004-12-31 2004-09-30 2004-06-30 2004-03-31 2003-12-31 
                                                                                               
          operating activities:
                                                                                               
          net income
        19,000,000 -300,000 4,000,000 27,500,000 15,600,000 4,300,000 27,200,000 15,500,000 1,400,000 4,200,000 24,100,000 14,500,000 500,000 4,900,000 21,500,000 -21,599,963.9 2,700,000 18,900,000 -18,599,967.8 300,000 3,100,000 15,200,000 11,400,000 2,300,000 4,000,000 26,500,000 2,800,000 3,600,000 15,600,000 2,300,000 3,100,000 12,400,000 10,200,000 3,500,000 2,500,000 10,900,000 9,300,000 1,700,000 1,700,000 13,600,000 9,400,000 1,600,000 1,100,000 12,600,000 10,300,000 600,000 -100,000 10,800,000 9,000,000 500,000 -300,000 9,000,000 10,000,000 -1,600,000 -700,000 8,700,000 5,200,000 -100,000 -2,000,000 6,500,000 1,200,000 -600,000 300,000 9,100,000 3,200,000 1,500,000 1,700,000 3,300,000 2,700,000 1,600,000 1,800,000 2,600,000 2,728 1,827 1,435 2,043 2,706 1,601 1,536 2,710 2,550 1,266 1,604 2,806 2,446 
          adjustments to reconcile net income to cash from operating activities:
                                                                                               
          depreciation and amortization
        23,000,000 22,200,000 21,800,000 21,700,000 20,900,000 19,100,000 18,100,000 18,000,000 17,300,000 16,800,000 16,600,000 16,700,000 15,700,000 16,600,000 14,800,000 15,500,000 -44,499,940.5 14,800,000 14,800,000 14,900,000 -40,699,945.5 13,700,000 13,500,000 13,500,000 13,000,000 12,800,000 12,400,000 13,800,000 12,400,000 12,700,000 12,300,000 10,800,000 11,900,000 12,500,000 11,500,000 11,600,000 11,700,000 11,800,000 11,600,000 11,400,000 11,300,000 11,400,000 10,900,000 10,800,000 10,200,000 10,200,000 9,500,000 9,600,000 9,200,000 9,400,000 9,200,000 8,900,000 8,700,000 8,300,000 6,800,000 6,900,000 7,700,000 7,900,000 8,500,000 6,200,000 7,100,000 7,100,000 8,100,000 6,600,000 6,400,000 6,300,000 4,800,000 4,600,000 4,500,000 5,200,000 4,400,000 4,500,000 4,400,000 4,500,000 4,097 3,452 4,341 4,179 3,814 5,007 5,076 5,226 5,009 4,664 4,393 4,764 5,004 
          deferred tax provision
        9,900,000 200,000 1,800,000 -2,300,000 1,200,000 10,900,000 -1,300,000 2,400,000 -900,000 -500,000 1,600,000 7,200,000 4,600,000 -800,000 100,000 7,100,000 -5,499,989.2 -700,000 6,200,000 -2,999,990.7 -1,800,000 100,000 4,700,000 4,200,000 900,000 200,000 8,200,000 1,000,000 -1,100,000 4,700,000 2,500,000 800,000 7,900,000 2,600,000 3,900,000 3,200,000 5,700,000  4,300,000 -9,500,000 8,800,000  500,000 700,000 7,000,000  200,000 400,000 5,400,000  -400,000 5,300,000  -2,000,000 4,500,000  4,400,000 -100,000 -5,200,000                    -1,772 5,563 -1,316 328 -1,409 5,365 
          changes in working capital items:
                                                                                               
          accounts receivable
        -33,600,000 2,400,000 29,500,000 -16,700,000  4,000,000 23,900,000 -8,900,000 -17,300,000 1,800,000 32,700,000 -18,400,000 -22,100,000 2,600,000 27,600,000 -15,000,000 -15,700,004.9 4,000,000 22,900,000 -11,200,000 -6,500,006.9 -300,000 14,300,000 -7,500,000 -15,700,000 9,300,000 25,200,000 -7,100,000 3,900,000 18,200,000 -7,000,000 -4,700,000 16,500,000 -4,700,000 -12,100,000 -200,000 15,100,000 -8,200,000 -4,400,000 6,900,000 33,600,000 -25,200,000 -19,100,000 3,300,000 24,600,000 -17,300,000 -17,000,000 5,600,000 21,700,000 -14,800,000 -15,200,000 1,000,000 16,200,000 -3,700,000 -13,800,000 2,500,000 12,800,000 -8,800,000 -9,700,000 700,000 12,400,000 -6,800,000 -6,300,000 3,700,000 21,000,000 -12,200,000 -8,100,000 -700,000 6,400,000 -4,000,000 -2,100,000 -1,100,000 6,700,000 -5,900,000 150 422 3,386 -2,873 -3,983 -1,598 3,784 -3,715 -2,407 -53 3,500 -1,698 -185 
          accrued revenue
        -17,700,000 -7,900,000 2,400,000 22,900,000 -12,000,000 500,000 6,300,000 -8,800,000 -6,100,000 3,100,000 11,200,000 1,200,000 -25,900,000 -1,300,000 10,700,000 4,900,000 -12,300,010.3 -4,000,000 100,000 16,200,000 -10,900,000.9 -4,200,000 3,700,000 11,400,000 -14,700,000 -3,200,000 8,100,000 14,500,000 -6,300,000 15,400,000 8,200,000 -2,600,000 4,700,000 8,200,000 -14,000,000 -3,600,000 10,200,000 -3,700,000 -9,600,000 -200,000 13,600,000 6,300,000 -17,100,000 2,000,000 16,200,000 7,000,000 -16,400,000 -1,900,000 4,700,000 20,400,000 -25,900,000 -3,900,000 6,700,000 19,200,000 -21,400,000 -9,200,000 7,900,000 12,800,000 -11,000,000 -13,200,000 4,900,000 16,600,000 -10,000,000 -3,000,000 16,500,000 9,400,000 -8,300,000 -500,000 -200,000 -1,300,000 -3,200,000 -500,000 3,000,000 1,800,000 -3,213 -905 -2,329 1,586 -3,790 1,463 -450 3,626 -4,147 930 735 2,757 -2,437 
          regulatory liabilities
        -4,500,000 -2,600,000 -2,800,000 6,600,000 -5,200,000 -2,100,000 6,600,000 4,400,000 -3,400,000 -1,500,000 1,400,000 2,000,000 -5,800,000 -5,100,000 10,300,000 6,100,000 -7,599,996 -4,000,000 2,400,000 9,200,000 -3,200,001.9 -2,000,000 2,100,000 3,100,000 -7,000,000 -4,100,000 3,500,000 3,500,000 -2,000,000 3,300,000 1,700,000 -1,600,000 3,800,000 2,400,000 -2,800,000 -2,700,000 -2,900,000 3,200,000 -12,500,000 -3,100,000 13,800,000 8,700,000 -4,300,000 -100,000 3,400,000 -1,700,000 -1,900,000                                       
          exchange gas receivable
        5,300,000 -6,000,000 -7,500,000 4,800,000 2,900,000 -3,500,000 -3,600,000 7,200,000 4,600,000 -4,600,000 -4,700,000 13,300,000 7,100,000 -11,700,000 -12,700,000 6,700,000 5,599,997.5 -5,300,000 -4,000,000 3,700,000 400,001.2 -2,300,000 -2,000,000 3,900,000 2,500,000 -3,300,000 -4,900,000 7,700,000 -4,600,000 -5,300,000 5,600,000 -3,600,000 -3,800,000 6,200,000 1,500,000 -1,800,000 -1,200,000 4,300,000 -500,000 -3,400,000 -3,200,000 11,000,000 -500,000 -6,200,000 -7,000,000 9,500,000 2,000,000 -5,200,000 -5,900,000 7,700,000                                      
          accounts payable
        19,000,000 1,700,000 -1,400,000 -12,300,000 13,500,000 -1,000,000 -700,000 -9,800,000 12,100,000 -1,100,000 -9,600,000 -22,300,000 33,400,000 900,000 -4,700,000 -13,400,000 3,700,019.2 -3,100,000 3,900,000 -4,500,000 12,499,995.6 400,000 -1,800,000 -11,100,000 14,700,000 1,000,000 -11,100,000 -9,600,000 2,700,000 -5,400,000 -11,400,000 1,100,000 -5,100,000 -4,300,000 9,300,000 1,700,000 -5,600,000 -6,300,000 12,100,000 2,200,000 -15,800,000 -9,400,000 24,900,000 -1,200,000 -11,300,000 -6,300,000 16,600,000 -200,000 -5,900,000 -5,100,000 13,800,000 1,200,000 -2,800,000 -7,700,000 10,400,000 200,000 -6,700,000 -4,000,000 10,500,000 -700,000 -1,100,000 -7,300,000 14,300,000 -500,000 -10,800,000 -6,400,000 11,000,000 -200,000 2,600,000 -2,000,000 2,600,000 -100,000 -2,800,000 -1,900,000 3,728 -3,620 5,013 -5,908 7,433 -727 -1,330 -1,025 2,805 -972 -1,740 1,132 1,190 
          other changes in working capital items
        -3,400,000 4,700,000 -3,100,000 -400,000 4,100,000 -1,800,000 -200,000 1,600,000 -2,300,000 9,400,000 -6,200,000 100,000 1,100,000 7,900,000 -5,400,000 -2,200,000 -2,699,999.3 6,000,000 -4,100,000 800,000 -900,002.4 8,900,000 -5,000,000 -3,000,000 7,000,000 700,000 -3,400,000 300,000 8,600,000 -8,500,000 3,600,000 2,900,000 -4,200,000 -1,200,000 -3,200,000 6,000,000 -6,000,000 2,200,000 -8,300,000 6,200,000 -4,300,000 1,000,000 -400,000 3,500,000 400,000 3,100,000 -1,200,000 4,800,000 -7,200,000 700,000 1,300,000 1,400,000 -1,500,000 -1,700,000 -5,000,000 6,100,000 -5,400,000 3,600,000 -6,500,000                             
          deferred regulatory and other charges
        4,200,000 800,000 -2,200,000 -6,400,000 -1,200,000 5,600,000 -2,300,000 -9,000,000 4,100,000 1,000,000 -2,700,000 -10,900,000 1,800,000 1,900,000 -4,300,000 -5,900,000 7,999,997.3 1,400,000 -1,700,000 -7,700,000 -5,300,009.3 6,100,000 -400,000 -400,000 -600,000 3,300,000 -1,100,000 -6,900,000 4,600,000 -2,400,000 -7,900,000 4,400,000 -1,800,000 -7,700,000 -2,400,000 5,100,000 700,000 -8,400,000 -4,700,000 2,400,000 12,000,000 -500,000 -6,700,000 5,400,000 1,600,000 -1,900,000 1,100,000 6,300,000 4,700,000 2,900,000 5,300,000 2,500,000 -4,200,000 -1,300,000 9,400,000 1,900,000 -2,500,000 -3,900,000 1,100,000   -10,600,000 -1,800,000                        
          other
        200,000 400,000 -300,000 6,700,000 2,500,000 -5,600,000 -1,200,000 2,300,000 4,700,000 -9,500,000 2,600,000 2,300,000 -9,400,000 200,000 600,000 3,800,000 -3,300,002.1 2,400,000 -300,000 1,200,000 1,300,004.3 -2,200,000 2,800,000 -1,900,000  400,000 1,400,000 300,000 -16,400,000 4,400,000 3,000,000 100,000 -200,000 5,800,000 1,300,000 700,000 300,000 2,700,000 5,400,000 -3,800,000 500,000 2,100,000 -1,800,000 -700,000 -1,500,000 1,400,000 3,200,000 -4,100,000 1,400,000 3,400,000 4,700,000 -2,200,000 -4,400,000 -1,500,000 3,000,000 -2,000,000 -3,300,000 400,000 100,000 -2,500,000 -1,100,000 3,100,000 600,000 -200,000 -1,900,000 8,900,000 400,000 -500,000 400,000 -900,000 100,000 1,200,000 1,900,000 -5,130 2,364 1,534 -346 -1,661 2,954 406 -503 -841 -3,044 3,044 -2,111 2,824 
          cash from operating activities
        21,400,000 15,600,000 42,200,000 52,100,000 23,300,000 26,100,000 49,900,000 26,600,000 28,300,000 16,300,000 47,100,000 15,300,000 15,000,000 11,700,000 41,900,000 29,100,000 -95,899,892.2 11,500,000 36,700,000 47,700,000 -74,899,924.3 16,600,000 30,400,000 27,900,000 12,700,000 20,100,000 34,300,000 37,800,000 6,700,000 34,900,000 28,400,000 11,500,000 25,700,000 37,500,000 5,600,000 22,500,000 26,000,000 14,200,000 4,200,000 20,400,000 62,700,000 27,800,000 1,400,000 19,000,000 34,900,000 28,700,000 12,200,000 13,800,000 29,500,000 40,800,000 4,800,000 9,000,000 22,500,000 30,400,000 -3,900,000 3,200,000 10,200,000 36,400,000 4,400,000 -5,500,000 2,700,000 24,300,000 29,700,000 2,500,000 13,700,000 5,000,000 20,200,000 7,300,000 11,900,000 7,900,000 3,200,000 6,600,000 10,900,000 6,100,000 3,230 6,172 10,277 694 3,076 7,251 4,924 8,825 1,984 7,900 5,698 15,066 1,878 
          capital expenditures
          free cash flows
        21,400,000 15,600,000 42,200,000 52,100,000 23,300,000 26,100,000 49,900,000 26,600,000 28,300,000 16,300,000 47,100,000 15,300,000 15,000,000 11,700,000 41,900,000 29,100,000 -95,899,892.2 11,500,000 36,700,000 47,700,000 -74,899,924.3 16,600,000 30,400,000 27,900,000 12,700,000 20,100,000 34,300,000 37,800,000 6,700,000 34,900,000 28,400,000 11,500,000 25,700,000 37,500,000 5,600,000 22,500,000 26,000,000 14,200,000 4,200,000 20,400,000 62,700,000 27,800,000 1,400,000 19,000,000 34,900,000 28,700,000 12,200,000 13,800,000 29,500,000 40,800,000 4,800,000 9,000,000 22,500,000 30,400,000 -3,900,000 3,200,000 10,200,000 36,400,000 4,400,000 -5,500,000 2,700,000 24,300,000 29,700,000 2,500,000 13,700,000 5,000,000 20,200,000 7,300,000 11,900,000 7,900,000 3,200,000 6,600,000 10,900,000 6,100,000 3,230 6,172 10,277 694 3,076 7,251 4,924 8,825 1,984 7,900 5,698 15,066 1,878 
          investing activities:
                                                                                               
          property, plant and equipment additions
        -57,700,000 -54,600,000 -40,200,000 -32,600,000 -55,600,000 -57,400,000 -36,700,000 -20,200,000 -47,600,000 -35,800,000 -35,400,000 -22,200,000 -39,600,000 -37,200,000 -29,900,000 -15,400,000 81,499,885 -39,000,000 -28,400,000 -14,100,000 93,599,877.4 -44,800,000 -32,000,000 -16,800,000 -42,500,000 -38,000,000 -27,800,000 -10,900,000 -39,100,000 -27,100,000 -10,100,000 -39,300,000 -27,400,000 -17,500,000 -23,700,000 -34,800,000 -28,300,000 -11,300,000 -33,000,000 -32,400,000 -25,400,000 -13,100,000 -31,900,000 -31,600,000 -19,900,000 -9,200,000 -24,900,000 -27,600,000 -22,600,000 -14,400,000 -21,100,000 -23,500,000 -14,800,000 -9,100,000 -14,400,000 -17,600,000 -14,300,000 -10,800,000 -15,800,000 -14,600,000 -8,900,000 -10,300,000 -15,700,000 -16,900,000 -8,100,000 -18,000,000 -7,700,000 -10,400,000 -5,700,000 -4,500,000 -6,600,000 -6,300,000 -10,000,000 -9,600,000 -8,989 -10,215 -8,812 -5,626 -7,687 -7,182 -5,054 -4,444 -5,848 -6,438 -6,269 -4,367  
          acquisitions, net of cash acquired
                                                                                               
          cash from investing activities
        -146,700,000 -54,600,000 -40,400,000 -103,800,000 -55,600,000 -57,400,000 -36,700,000 -20,200,000                -16,800,000    2,500,000                                                         -6,269 -4,367 -5,277 
          financing activities:
                                                                                               
          proceeds (repayment of) from short-term debt
                                                                                               
          issuance of long-term debt
                           -94,999,900.3    29,800,000                                                              
          repayment of long-term debt
        -2,100,000 -1,500,000 -1,300,000 -2,100,000 -1,500,000 -1,300,000 -2,000,000 -2,100,000 -1,600,000 -1,200,000 -5,500,000 -2,100,000 -1,500,000 -1,300,000 20,299,974.2 -13,000,000 -100,000 -7,200,000 15,899,975.2 -1,500,000 -14,400,000 -3,600,000 -1,800,000 -13,400,000 -100,000 -13,400,000 -200,000 -200,000 -18,500,000 -200,000 -100,000 -200,000 -7,000,000 -200,000 -200,000 -4,000,000 -200,000 -100,000 -100,000 -200,000 -100,000 -100,000 -100,000 -200,000 -100,000 -100,000 -100,000             -200,000    -200,000    -80 -79 -76 -75 -73 -72 -71 -70   -66 -3,064 -61 
          long-term debt issuance costs
           -100,000               499,999.4                                                                   
          increase in capital lease obligations
                100,000 200,000    -100,000    100,000    200,000           -800,000 -700,000    2,200,000                                                
          net increase in exchange gas financing
        -3,900,000 5,200,000   -2,700,000    -4,400,000 4,400,000   -6,800,000 10,600,000   -5,199,997.7 4,800,000   -500,001.1    -2,500,000              300,000                                                 
          dividends paid
        -8,100,000 -7,400,000 -7,300,000 -7,300,000 -6,900,000 -6,900,000 -6,900,000 -6,800,000 -6,600,000 -6,500,000 -6,600,000 -6,500,000 -6,200,000 -6,300,000 -6,300,000 -6,300,000 17,499,976.4 -6,000,000 -5,700,000 -5,800,000 16,899,977.4 -5,600,000 -5,700,000 -5,600,000 -5,400,000 -5,700,000 -5,500,000 -5,500,000 -5,400,000 -5,500,000 -5,400,000 -5,100,000 -5,100,000 -5,100,000 -5,000,000 -5,000,000 -5,000,000 -5,000,000 -4,900,000 -4,900,000 -4,900,000 -4,900,000 -4,800,000 -4,800,000 -4,800,000 -4,800,000 -4,800,000 -4,800,000 -4,700,000 -4,800,000 -4,800,000 -4,800,000 -3,800,000 -3,800,000 -3,800,000 -3,800,000 -3,800,000 -3,800,000 -3,700,000 -3,700,000 -3,800,000 -3,800,000 -3,800,000 -3,800,000 -2,800,000 -2,800,000 -2,000,000 -2,100,000 -2,000,000 -2,000,000 -1,900,000 -2,000,000 -2,000,000 -2,000,000 -1,992 -1,977 -1,973 -1,966 -1,966 -1,964 -1,960 -1,953 -1,970 -1,966 -1,964 -1,957 -1,954 
          proceeds from issuance of common stock
        100,000 71,400,000 1,700,000 300,000 400,000 100,000 300,000 300,000 300,000 200,000 300,000 300,000 200,000 300,000 200,000 300,000 -45,299,954.5 44,800,000 200,000 300,000 -799,998.9 300,000 200,000 300,000 200,000 300,000 300,000 300,000 300,000 300,000 300,000 300,000 400,000 300,000 300,000 300,000 400,000 300,000 300,000 400,000 300,000 300,000 300,000 300,000 300,000 300,000 200,000 300,000 300,000 300,000 300,000 500,000 65,700,000 300,000 300,000 200,000 200,000 300,000 200,000 200,000 300,000 200,000 200,000 50,800,000 5,400,000                      
          construction advances
                                                                                               
          cash from financing activities
        126,300,000 45,100,000 -3,500,000 55,600,000 32,300,000 34,800,000 -16,700,000 -6,600,000 19,800,000   4,700,000 25,700,000 28,300,000   11,600,007.7    -21,699,952.3    27,700,000          19,500,000                    17,900,000    12,300,000    -15,200,000 19,900,000 -9,800,000 16,000,000 203,900,000 3,800,000 -5,900,000 -4,000,000 3,800,000 1,700,000 -1,500,000 1,700,000 6,494 4,010 176 3,938          
          net increase in cash and cash equivalents
        1,000,000 6,100,000 -1,700,000 3,900,000     500,000   -2,200,000 1,100,000    -2,799,999.5   100,000 -2,999,999.2   1,000,000    -3,500,000   600,000     -3,500,000    -7,200,000 4,900,000 2,800,000  -1,900,000                                            
          cash and cash equivalents at beginning of year
                                                                                               
          cash and cash equivalents at end of year
                                                                                               
          supplemental information:
                                                                                               
          interest paid
        9,100,000 10,400,000 9,400,000 10,400,000 7,600,000 6,900,000 9,700,000 7,000,000 8,900,000 6,500,000 8,800,000 6,700,000 8,300,000 4,900,000 8,100,000 4,700,000 -17,899,974 4,700,000 8,300,000 4,900,000 -15,299,976.3 2,700,000 9,000,000 3,600,000 8,500,000 2,900,000 9,100,000 3,600,000 3,200,000 8,800,000 3,600,000 3,800,000 7,400,000 4,000,000 7,900,000 2,800,000 8,500,000 2,900,000 7,400,000 2,900,000 8,900,000 3,100,000 7,300,000 2,900,000 7,600,000 3,000,000 7,600,000 2,800,000 7,500,000 2,900,000 7,700,000 2,700,000 7,700,000 3,100,000 7,400,000 3,000,000 7,700,000 3,100,000 8,000,000 2,800,000 7,700,000 2,000,000 7,700,000 1,900,000 7,100,000 2,600,000 4,500,000 1,900,000 4,000,000 2,100,000 4,600,000 1,900,000 3,700,000 2,000,000 3,672 1,660 3,816 1,542 3,301 1,469 3,225 1,460 14,962 -1,386 -6,127 1,603 2,786 
          income taxes paid
        1,900,000         100,000 700,000 400,000 -1,399,998.6 400,000 700,000 300,000 -799,999.1 200,000   -100,000   200,000 200,000    600,000 1,000,000 300,000 100,000 1,400,000 900,000 300,000 800,000  100,000 600,000  -400,000 -6,900,000 1,300,000 1,000,000 -4,400,000 100,000   -1,000,000 300,000 200,000 2,000,000 1,500,000 1,800,000 448 760 1,090 803 1,000 1,851        
          payments on capital leases
        100,000   100,000   100,000 100,000 100,000 100,000 -199,999.8 100,000 100,000 -199,999.7 100,000 100,000 100,000 100,000 4,500,000 800,000 800,000 700,000 800,000 800,000 800,000 900,000 800,000 900,000 800,000 900,000                                                  
          capital expenditures included in accounts payable
        -3,300,000 900,000 3,300,000 7,200,000 -100,000 6,000,000 500,000 5,300,000 -1,100,000 3,300,000 -300,000 5,600,000 1,900,000 1,500,000 -700,000 4,600,000 -4,199,995.1 300,000 -200,000 4,100,000 -599,998.3 -300,000 400,000 500,000 -200,000 100,000 700,000 800,000 -100,000 500,000 900,000 300,000 600,000 -1,100,000 -500,000 1,400,000 500,000 -800,000 200,000 600,000 400,000 -1,400,000 1,300,000 400,000 -400,000 -700,000 800,000 1,000,000                                      
          right of use assets obtained in exchange for lease obligations
                                                                                               
          acquisition, net of cash acquired
         -200,000 -71,200,000                                                                                    
          proceeds from (repayment of) short-term debt
         -53,900,000         -8,500,000 24,200,000 44,000,000          3,300,000 13,000,000       7,000,000           2,700,000                    -45,200,000 10,500,000 23,400,000 -57,100,000 13,600,000 52,400,000 8,900,000 -3,900,000 -2,100,000             5,930 935    
          decrease in capital lease obligations
                      99,999.9        -200,000 300,000 -4,500,000 -900,000 -700,000 -800,000 -800,000 -400,000 -600,000 -800,000                                                      
          cash and cash equivalents at beginning of period
         6,300,000  6,500,000  9,000,000  6,500,000  6,000,000  5,200,000  7,800,000 8,900,000 5,800,000  8,700,000  8,400,000                                             
          cash and cash equivalents at end of period
         6,100,000 -1,700,000 10,200,000  3,500,000 -3,500,000 6,300,000  -800,000 6,800,000  2,800,000 -1,400,000 6,500,000  3,800,000 -1,100,000 6,100,000  4,000,000 -2,000,000 6,200,000  2,500,000 500,000 4,300,000 -2,200,000 -1,000,000 9,500,000 3,100,000 -1,000,000 8,800,000  -3,500,000 -200,000 8,100,000  -7,200,000 4,900,000 11,200,000  -1,900,000                                            
          supplemental cash flow information:
                                                                                               
          non-cash investing activity:
                                                                                               
          right-of-use assets obtained in exchange for lease obligations
             500,000 600,000 300,000 400,000 1,400,000 -100,000 700,000 -100,000 600,000 -899,999.3 500,000 200,000 200,000 -1,599,998.8 1,100,000 -400,000 900,000 -200,000 600,000 -300,000 3,900,000                                                            
          proceeds from short-term debt
           67,100,000    7,900,000 32,500,000                             5,900,000                                    3,700,000              
          net decrease in exchange gas financing
           -3,200,000   3,500,000 -6,700,000    -12,300,000    -6,200,000    -3,500,000   2,000,000 -3,600,000   4,700,000 -7,300,000  5,200,000 -5,400,000  3,600,000 -5,900,000  1,700,000 1,200,000 -3,900,000   3,000,000 -10,500,000  5,800,000 6,600,000 -8,800,000   5,600,000 -7,200,000                                      
          (repayment of) proceeds from short-term debt
            41,500,000 -93,500,000             -7,600,000 -17,400,000     9,400,000   -17,000,000     2,600,000 -5,300,000                                                      
          proceeds from issuance of long-term debt
                                                                     40,000,000                        
          net decrease in cash and cash equivalents
             3,500,000 -3,500,000 -200,000                  2,500,000                                                              
          cash (used in) investing activities
                 -35,800,000 -35,400,000 -22,200,000  -37,200,000 -29,900,000 -15,400,000  -39,000,000 -28,400,000 -14,100,000  -44,800,000    -38,000,000   -39,100,000 -27,100,000 -10,100,000 -39,300,000 -27,400,000 -17,500,000  -34,800,000 -28,300,000 -11,300,000  -32,400,000 -25,400,000 -13,100,000 -31,900,000 -31,600,000 -19,900,000 -9,200,000 -24,900,000 -27,600,000 -22,600,000 -14,400,000 -21,100,000 -23,500,000 -14,800,000 -9,100,000 -14,400,000 -17,600,000 -14,300,000 -10,800,000 -15,800,000 -14,600,000 -8,900,000 -10,300,000 -15,800,000 -23,700,000 -8,100,000 -18,000,000  -10,400,000 -5,700,000 -4,500,000 -6,600,000 -6,300,000 -10,000,000 -9,600,000  -10,215 -8,812 -5,626  -7,182 -5,054 -4,444      
          cash (used in) financing activities
                       -13,700,000   -9,400,000 -33,500,000   -400,000 -10,100,000   -6,000,000 -43,800,000  -8,800,000 -17,700,000  700,000 -17,000,000   2,100,000 -3,500,000  4,800,000 -32,400,000 -11,900,000  10,700,000 -17,300,000 -14,600,000  19,000,000 -7,300,000 -28,700,000  17,200,000 -9,100,000 -20,600,000   3,300,000 -27,900,000   3,700,000 -12,900,000                  156        
          net (decrease) in cash and cash equivalents
                                                                                               
          repayment of short-term debt
                      -17,800,000 -100,000                        4,100,000    8,700,000 -24,200,000 -1,000,000  19,100,000 -8,100,000 -16,800,000  19,100,000 -72,600,000 -10,300,000  14,100,000 700,000 -16,200,000  21,700,000                     1,215 -1,400    -6,980  
          adjustments to reconcile net income to cash
                                                                                               
          provided by operating activities:
                                                                                               
          gain on divestiture
                                -13,400,000                                                            
          proceeds from divestiture
                                13,400,000                                                            
          non-cash additions to property, plant and equipment
                                                                                               
          net increasein cash and cash equivalents
                                       3,100,000                                                        
          taxes payable
                                           -1,700,000    -4,200,000                            -500,000 -2,100,000 2,900,000  1,100,000 300,000 1,200,000              
          net increase / (decrease) in cash and cash equivalents
                                         3,000,000                                                      
          net increase in cash
                                                     4,900,000 -2,900,000   -2,300,000 300,000   700,000 -400,000   -2,300,000 900,000   1,100,000 -1,300,000   3,000,000 6,500,000     2,000,000   735 -33 1,641 -994 -353 225 -829 1,132 -789     
          cash at beginning of year
                                                                                               
          cash at end of year
                                                                                               
          balance at january 1, 2014
                                                     232,100,000                                          
          net income for 2014
                                                                                               
          dividends
                                                                                               
          shares issued under stock plans
                                                                                               
          issuance of 38,020 common shares
                                                                                               
          balance at december 31, 2014
                                                                                               
          net income for 2015
                                                                                               
          issuance of 36,265 common shares
                                                                                               
          balance at december 31, 2015
                                                                                               
          net income for 2016
                                                                                               
          issuance of 32,095 common shares
                                                                                               
          balance at december 31, 2016
                                                                                               
          (decrease) / increase in capital lease obligations
                                             -600,000                                                  
          net (decrease) / increase in cash and cash equivalents
                                             -600,000                                                  
          deferred taxes provision
                                                                         -1,800,000                      
          taxes refundable / payable
                                                          200,000   -600,000 400,000 200,000 300,000 7,600,000                  665 -1,274 2,195  -561        
          increase / (decrease) in capital lease obligations
                                                 700,000 900,000 900,000                                            
          balance at january 1, 2013
                                                     230,000,000                                          
          net income for 2013
                                                                                               
          issuance of 39,559 common shares
                                                                                               
          balance at december 31, 2013
                                                                                               
          retirement of preferred stock
                                                                                 -1 -21 -222       
          balance at january 1, 2012
                                                                                               
          net income for 2012
                                                                                               
          issuance of 41,752 common shares
                                                                                               
          issuance of 2,760,000 common shares
                                                                                               
          balance at december 31, 2012
                                                                                               
          cash at beginning of period
                                                     9,400,000  9,800,000  7,500,000  8,900,000  7,700,000  11,500,000  4,600,000  4,600,000  3,207  3,032  3,766  
          cash at end of period
                                                     14,300,000  5,200,000 -400,000 7,500,000  2,700,000 -1,400,000 8,200,000  2,100,000 -800,000 6,600,000  1,700,000 -2,500,000 8,800,000  -1,300,000 -4,200,000 14,500,000  700,000 300,000 4,000,000  2,000,000 -600,000 2,800,000  -33 1,641 2,213  225 -829 4,164  430 831 2,560  
          dividends on common shares
                                                                                               
          stock compensation plans
                                                     700,000                                          
          issuance of 9,868 common shares
                                                     300,000                                          
          balance at march 31, 2014
                                                     233,100,000                                          
          issuance of 10,922 common shares
                                                     300,000                                          
          balance at march 31, 2013
                                                     230,700,000                                          
          net increase in gas inventory financing
                                                          -2,000,000    -500,000    -4,500,000                             
          balance at january 1, 2011
                                                                                               
          net income for 2011
                                                                                               
          issuance of 39,473 common shares
                                                                                               
          balance at december 31, 2011
                                                                                               
          regulatory assets consist of the following
                                                                                              
          energy supply & other regulatory tracker mechanisms
                                                       1,600,000                                        
          deferred restructuring costs
                                                       -2,900,000                                        
          retirement benefit obligations
                                                       200,000                                        
          income taxes
                                                       -200,000                                        
          environmental obligations
                                                       -600,000                                        
          deferred storm charges
                                                       -1,600,000                                        
          total regulatory assets
                                                       -3,600,000                                        
          less: current portion of regulatory assets
                                                       1,400,000                                        
          regulatory assets – noncurrent
                                                       -5,000,000                                        
          net decrease in cash
                                                                                            831 -1,206  
          regulatory assets – current
                                                         27,300,000                                      
          unbilled revenues
                                                         10,400,000                                      
          total accrued revenue
                                                         37,700,000                                      
          gas inventory
                                                          1,800,000 -3,200,000 -2,300,000 8,000,000 800,000 -7,300,000 -7,600,000 9,900,000 5,300,000 -4,800,000 -4,500,000 7,700,000 49,600,000                        
          income taxes (refunded) paid
                                                                                               
          balance at january 1, 2010
                                                                                               
          net income for 2010
                                                                                               
          issuance of 41,455 common shares
                                                                                               
          balance at december 31, 2010
                                                                                               
          level 1 –
                                                                                               
          level 2 –
                                                                                               
          level 3 –
                                                                                               
          net decrease in gas inventory financing
                                                            2,000,000 -6,500,000   6,600,000 -7,800,000   2,200,000 -3,800,000                          
          fair value amount (millions) offset in regulatory assets, as of:
                                                                                               
          description
                                                                                               
          natural gas futures contracts
                                                                                               
          total
                                                                                               
          acquisitions
                                                                                               
          proceeds from issuance (repayment) of long-term debt
                                                                 -100,000                              
          balance at january 1, 2009
                                                                                               
          net income for 2009
                                                                                               
          issuance of 43,615 common shares
                                                                                               
          issuance of 2,970,000 common shares
                                                                                               
          balance at december 31, 2009
                                                                                               
          proceeds from issuance (repayment of) long-term debt
                                                               -100,000                               
          fair value amount offset in regulatory assets, as of:
                                                                                               
          net (decrease) in cash
                                                                            300,000 -600,000    -1,800,000              
          refundable taxes
                                                                                         3,719 -3,907 3,748 -1,159 4,157  
          balance at january 1, 2008
                                                                                               
          net income for 2008
                                                                                               
          issuance of 32,754 common shares
                                                                                               
          issuance of 2,000,000 common shares
                                                                                               
          balance at december 31, 2008
                                                                                               
          acquisition costs
                                                                                               
          changes in current assets and liabilities:
                                                                                               
          all other current assets and liabilities
                                                                    -6,400,000 6,800,000 10,600,000 -10,200,000 -6,500,000 2,500,000 3,800,000   2,600,000 -1,200,000 1,200,000 -1,900,000 2,400,000              
          balance sheet location
                                                                                               
          fair value
                                                                     1,900,000                          
          amount of gain recognized in regulatory asset / liability for derivatives
                                                                     -3,100,000                          
          balance at january 1, 2007
                                                                                               
          net income for 2007
                                                                                               
          issuance of 38,303 common shares
                                                                                               
          balance at december 31, 2007
                                                                                               
          deferred taxes
                                                                       7,700,000    1,200,000 1,400,000 -200,000 1,600,000 -200,000 -1,800,000 -500,000  -221 388 -1,352  11        
          equity purchase price
                                                                                              
          plus: working capital adjustment
                                                                                              
          aggregate purchase price
                                                                                              
          transaction and transition costs
                                                                       1,400,000                        
          total cash purchase price
                                                                       1,400,000                        
          allocation to:
                                                                                               
          book value of net utility plant
                                                                                              
          cash acquired
                                                                                              
          accounts receivable and other current assets
                                                                                              
          regulatory and other noncurrent assets
                                                                       -1,400,000                        
          accounts payable and other current liabilities
                                                                                              
          plant acquisition adjustment
                                                                                              
          declaration date
                                                                                               
          03/26/09
                                                                         5,000,000                      
          01/15/09
                                                                         2,000,000                      
          09/25/08
                                                                         10,000,000                      
          06/19/08
                                                                         8,000,000                     
          03/20/08
                                                                         5,000,000  5,000,000                  
          01/17/08
                                                                         2,000,000  2,000,000                  
          deferred restructuring charges
                                                                          200,000 700,000 700,000 1,000,000          -2,278 -644 -2,161      
          issuance of common stock
                                                                           200,000 300,000 200,000 200,000 800,000 200,000 300,000 244 244 268 245 225 260 247 299 229 237 237 244 17,152 
          acquisition-related expenditures
                                                                                               
          09/13/07
                                                                           11,000,000                  
          06/21/07
                                                                           8,000,000                 
          03/22/07
                                                                           5,000,000  5,000,000              
          01/18/07
                                                                           2,000,000  2,000,000              
          proceeds from (repayment of) long-term debt
                                                                                               
          taxes payable /
                                                                                               
          balance at january 1, 2005
                                                                                               
          net income for 2005
                                                                                               
          dividends on preferred shares
                                                                                               
          issuance of 38,003 common shares
                                                                                               
          balance at december 31, 2005
                                                                                               
          net income for 2006
                                                                                               
          issuance of 40,365 common shares
                                                                                               
          balance at december 31, 2006
                                                                                               
          exercised stock options – 42,437 common shares
                                                                                               
          09/29/06
                                                                               11,000,000              
          06/22/06
                                                                               8,000,000             
          03/23/06
                                                                               5,000,000           
          01/12/06
                                                                               2,000,000           
          proceeds from (repayment) of short-term debt
                                                                                   -9,075            
          deferred tax benefit
                                                                                               
          repayment of capital lease obligations
                                                                                  -104 -102 53 -69 -103 -103 -119 -125   -158 -148 -268 
          balance at january 1, 2004
                                                                                               
          net income for 2004
                                                                                               
          issuance of 35,310 common shares
                                                                                               
          balance at december 31, 2004
                                                                                               
          cash flow from operating activities:
                                                                                               
          materials and supplies
                                                                                   -739 -890 1,075 34 -752 -1,005 1,128 439 -472 -863 677  
          prepayments and other
                                                                                   708 -605 316 -246 751 -616 270 3,461 1,499 -3,599 3,014  
          refundable customer deposits
                                                                                   100 -7 58 93 181 93 119      
          interest payable
                                                                                     1,088 -842   867 -867 867 -692 664  
          other current liabilities
                                                                                   264 463 -923 363 332 280 336 110 783 147 313 -429 
          deferred restructuring and other charges
                                                                                   744 -90 -444          
          cash flows from investing activities:
                                                                                               
          cash flows from financing activities:
                                                                                               
          09/23/05
                                                                                   11          
          06/17/05
                                                                                           
          03/24/05
                                                                                         
          01/13/05
                                                                                         
          issuance (repayment) of short-term debt
                                                                                     6,025          
          supplemental schedule of noncash activities:
                                                                                               
          capital leases incurred
                                                                                             14 
          balance at january 1, 2003
                                                                                               
          net income for 2003
                                                                                               
          common stock offering—717,600 shares
                                                                                               
          issuance of 28,714 common shares
                                                                                               
          balance at december 31, 2003
                                                                                               
          09/24/04
                                                                                       11      
          06/24/04
                                                                                           
          03/31/04
                                                                                         
          01/15/04
                                                                                         
          cash (used in financing) activities
                                                                                         -3,249      
          income taxes refunded
                                                                                         478    1,333  
          gain on sale of investments
                                                                                               
          proceeds from the sale of investments
                                                                                               
          balance at january 1, 2002
                                                                                               
          net income for 2002
                                                                                               
          redemption premium on preferred shares
                                                                                               
          balance at december 31, 2002
                                                                                               
          (repayment of) long-term debt
                                                                                               
          (retirement of) preferred stock
                                                                                               
          (repayment of) capital lease obligations
                                                                                               
          income taxes (paid) refunded
                                                                                           -501    
          09/26/03
                                                                                           11  
          06/26/03
                                                                                            
          03/21/03
                                                                                            
          01/16/03
                                                                                            
          cash from (used in financing) activities
                                                                                            1,402 -11,905  
          (gain) loss on sale of investments
                                                                                               
          proceeds from the sale of electric generation assets
                                                                                               
          balance at january 1, 2001
                                                                                               
          net income after extraordinary item for 2001
                                                                                               
          issuance of 11,279 common shares
                                                                                               
          re-acquired and retired common shares
                                                                                               
          balance at december 31, 2001
                                                                                               
          gain on sale of investment
                                                                                               
          prepayments and other current assets
                                                                                               
          acquisition of property, plant and equipment
                                                                                               
          declaration
                                                                                               
          date
                                                                                               
          09/27/02
                                                                                               
          06/20/02
                                                                                               
          03/21/02
                                                                                               
          01/17/02