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v3.19.3.a.u2

Segment Information (Details) - USD ($) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues | $ 140,941,000 | $ 138,198,000 | $ 122,147,000 | $ 167,569,000 | $ 140,079,000 | $ 137,795,000 | $ 124,262,000 | $ 157,632,000 | $ 568,855,000 | $ 559,768,000 | $ 563,099,000 |
Depreciation and amortization |  |  |  |  |  |  |  |  | (71,562,000) | (56,412,000) | (53,077,000) |
Other operating expenses |  |  |  |  |  |  |  |  | (386,383,000) | (389,149,000) | (385,397,000) |
Operating Income (Loss) | 21,877,000 | 38,738,000 | 19,783,000 | 30,512,000 | 23,990,000 | 39,798,000 | 24,231,000 | 26,188,000 | 110,910,000 | 114,207,000 | 124,625,000 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 18,811,000 | 17,055,000 | 14,399,000 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | (23,063,000) | (19,609,000) | (19,324,000) |
Income before income taxes |  |  |  |  |  |  |  |  | 106,658,000 | 111,653,000 | 119,700,000 |
Income tax (provision) benefit | (3,116,000) | (7,454,000) | (3,505,000) | (5,709,000) | (5,642,000) | (9,597,000) | (5,828,000) | (6,367,000) | (19,784,000) | (27,434,000) | (22,094,000) | [1]
Net Income Including Noncontrolling Interest |  |  |  |  |  |  |  |  | 86,874,000 | 84,219,000 | 97,606,000 |
Net Income | 16,662,000 | $ 30,657,000 | $ 15,548,000 | $ 24,007,000 | 16,361,000 | $ 29,506,000 | $ 18,351,000 | $ 20,001,000 | 86,874,000 | 84,219,000 | 97,606,000 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 2,081,664,000 |  |  |  | 1,988,618,000 |  |  |  | 2,081,664,000 | 1,988,618,000 | 1,855,182,000 | [2]
Capital expenditures |  |  |  |  |  |  |  |  | 164,036,000 | 212,197,000 | 108,131,000 |
Effects Of The Tax Cuts And Jobs Act [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Net Deferred Income Tax Benefit Tax Cuts And Jobs Act |  |  |  |  |  |  |  |  |  |  | 21,700,000 |
Investment in ATC | 71,648,000 |  |  |  | 66,339,000 |  |  |  | 71,648,000 | 66,339,000 | 20,400,000 |
Electric [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 408,285,000 | 400,882,000 | 413,926,000 |
Gas [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 159,875,000 | 157,767,000 | 148,825,000 |
Non Regulated Energy [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 695,000 | 1,119,000 | 348,000 |
Transmission Investment [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
All Others [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Operating Segments [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 568,855,000 | 559,768,000 | 563,099,000 |
Operating Segments [Member] | Electric [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 409,091,000 | 400,593,000 | 413,416,000 |
Depreciation and amortization |  |  |  |  |  |  |  |  | (52,755,000) | (38,925,000) | (36,660,000) |
Other operating expenses |  |  |  |  |  |  |  |  | (297,156,000) | (297,374,000) | (308,100,000) |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 59,180,000 | 64,294,000 | 68,656,000 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 7,153,000 | 7,294,000 | 4,539,000 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | (14,978,000) | (12,198,000) | (11,257,000) |
Income before income taxes |  |  |  |  |  |  |  |  | 51,355,000 | 59,390,000 | 61,938,000 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | (5,037,000) | (13,453,000) | (20,547,000) |
Net Income |  |  |  |  |  |  |  |  | 46,318,000 | 45,937,000 | 41,391,000 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 1,308,277,000 |  |  |  | 1,193,083,000 |  |  |  | 1,308,277,000 | 1,193,083,000 | 1,058,988,000 |
Capital expenditures |  |  |  |  |  |  |  |  | 125,086,000 | 176,399,000 | 77,353,000 |
Operating Segments [Member] | Gas [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 175,945,000 | 173,843,000 | 163,799,000 |
Depreciation and amortization |  |  |  |  |  |  |  |  | (11,320,000) | (10,060,000) | (9,000,000) |
Other operating expenses |  |  |  |  |  |  |  |  | (145,097,000) | (145,883,000) | (135,028,000) |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 19,528,000 | 17,900,000 | 19,771,000 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 3,550,000 | 3,132,000 | 1,911,000 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | (4,237,000) | (3,692,000) | (3,234,000) |
Income before income taxes |  |  |  |  |  |  |  |  | 18,841,000 | 17,340,000 | 18,448,000 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | (4,753,000) | (4,474,000) | (7,303,000) |
Net Income |  |  |  |  |  |  |  |  | 14,088,000 | 12,866,000 | 11,145,000 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 408,001,000 |  |  |  | 377,005,000 |  |  |  | 408,001,000 | 377,005,000 | 354,875,000 |
Capital expenditures |  |  |  |  |  |  |  |  | 36,193,000 | 30,497,000 | 26,847,000 |
Operating Segments [Member] | Non Regulated Energy [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 40,715,000 | 40,645,000 | 44,816,000 |
Depreciation and amortization |  |  |  |  |  |  |  |  | (7,487,000) | (7,427,000) | (7,417,000) |
Other operating expenses |  |  |  |  |  |  |  |  | (144,000) | (144,000) | (190,000) |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 33,084,000 | 33,074,000 | 37,209,000 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | (5,083,000) | (5,307,000) | (5,533,000) |
Income before income taxes |  |  |  |  |  |  |  |  | 28,001,000 | 27,767,000 | 31,676,000 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | (7,628,000) | (7,534,000) | 8,860,000 | [1]
Net Income |  |  |  |  |  |  |  |  | 20,373,000 | 20,233,000 | 40,536,000 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 258,004,000 |  |  |  | 265,301,000 |  |  |  | 258,004,000 | 265,301,000 | 270,384,000 |
Capital expenditures |  |  |  |  |  |  |  |  | 2,757,000 | 5,301,000 | 3,931,000 |
Effects Of The Tax Cuts And Jobs Act [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Net Deferred Income Tax Benefit Tax Cuts And Jobs Act |  |  |  |  |  |  |  |  |  |  | 21,700,000 |
Operating Segments [Member] | Transmission Investment [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Depreciation and amortization |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Other operating expenses |  |  |  |  |  |  |  |  | 0 | (16,000) | (9,000) |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 0 | (16,000) | (9,000) |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 9,547,000 | 8,602,000 | 9,844,000 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Income before income taxes |  |  |  |  |  |  |  |  | 9,547,000 | 8,586,000 | 9,835,000 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | (2,602,000) | (2,345,000) | (3,954,000) |
Net Income |  |  |  |  |  |  |  |  | 6,945,000 | 6,241,000 | 5,881,000 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 71,668,000 |  |  |  | 66,366,000 |  |  |  | 71,668,000 | 66,366,000 | 61,783,000 | [2]
Capital expenditures |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Effects Of The Tax Cuts And Jobs Act [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Investment in ATC |  |  |  |  |  |  |  |  |  |  | 20,400,000 |
Operating Segments [Member] | All Others [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Depreciation and amortization |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Other operating expenses |  |  |  |  |  |  |  |  | (882,000) | (1,045,000) | (1,002,000) |
Operating Income (Loss) |  |  |  |  |  |  |  |  | (882,000) | (1,045,000) | (1,002,000) |
Other (deductions) income, net |  |  |  |  |  |  |  |  | (1,439,000) | (1,973,000) | (1,895,000) |
Interest (expense) income, net |  |  |  |  |  |  |  |  | 1,235,000 | 1,588,000 | 700,000 |
Income before income taxes |  |  |  |  |  |  |  |  | (1,086,000) | (1,430,000) | (2,197,000) |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | 236,000 | 372,000 | 850,000 |
Net Income |  |  |  |  |  |  |  |  | (850,000) | (1,058,000) | (1,347,000) |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 443,278,000 |  |  |  | 465,661,000 |  |  |  | 443,278,000 | 465,661,000 | 485,548,000 |
Capital expenditures |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Consolidation/Elimination Entries [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | (56,896,000) | (55,313,000) | (58,932,000) |
Depreciation and amortization |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Other operating expenses |  |  |  |  |  |  |  |  | 56,896,000 | 55,313,000 | 58,932,000 |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Income before income taxes |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Net Income |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | (407,564,000) |  |  |  | (378,798,000) |  |  |  | (407,564,000) | (378,798,000) | (376,396,000) |
Capital expenditures |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Consolidation/Elimination Entries [Member] | Electric [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 806,000 | (289,000) | (510,000) |
Consolidation/Elimination Entries [Member] | Gas [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 16,070,000 | 16,076,000 | 14,974,000 |
Consolidation/Elimination Entries [Member] | Non Regulated Energy [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 40,020,000 | 39,526,000 | 44,468,000 |
Consolidation/Elimination Entries [Member] | Transmission Investment [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Consolidation/Elimination Entries [Member] | All Others [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
MGE [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 568,855,000 | 559,768,000 | 563,111,000 |
Depreciation and amortization |  |  |  |  |  |  |  |  | (71,562,000) | (56,412,000) | (53,077,000) |
Other operating expenses |  |  |  |  |  |  |  |  | (385,501,000) | (388,088,000) | (384,398,000) |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 111,792,000 | 115,268,000 | 125,636,000 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 10,703,000 | 10,426,000 | 6,450,000 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | (24,298,000) | (21,197,000) | (20,024,000) |
Income before income taxes |  |  |  |  |  |  |  |  | 98,197,000 | 104,497,000 | 112,062,000 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | (17,418,000) | (25,461,000) | (18,990,000) | [3]
Net Income Including Noncontrolling Interest |  |  |  |  |  |  |  |  | 80,779,000 | 79,036,000 | 93,072,000 |
Less Net Income Attributable to Noncontrolling Interest, net of tax |  |  |  |  |  |  |  |  | (22,349,000) | (22,552,000) | (43,237,000) |
Net Income |  |  |  |  |  |  |  |  | 58,430,000 | 56,484,000 | 49,835,000 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 1,973,477,000 |  |  |  | 1,834,891,000 |  |  |  | 1,973,477,000 | 1,834,891,000 | 1,684,041,000 |
Capital expenditures |  |  |  |  |  |  |  |  | 164,036,000 | 212,197,000 | 108,131,000 |
Effects Of The Tax Cuts And Jobs Act [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Net Deferred Income Tax Benefit Tax Cuts And Jobs Act |  |  |  |  |  |  |  |  |  |  | 21,700,000 |
Investment in ATC | 0 |  |  |  | 0 |  |  |  | 0 | 0 |  |
MGE [Member] | Electric [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 408,285,000 | 400,882,000 | 413,929,000 |
MGE [Member] | Gas [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 159,875,000 | 157,767,000 | 148,834,000 |
MGE [Member] | Non Regulated Energy [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 695,000 | 1,119,000 | 348,000 |
MGE [Member] | Operating Segments [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 568,855,000 | 559,768,000 | 563,111,000 |
MGE [Member] | Operating Segments [Member] | Electric [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 409,091,000 | 400,593,000 | 413,416,000 |
Depreciation and amortization |  |  |  |  |  |  |  |  | (52,755,000) | (38,925,000) | (36,660,000) |
Other operating expenses |  |  |  |  |  |  |  |  | (297,156,000) | (297,374,000) | (308,100,000) |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 59,180,000 | 64,294,000 | 68,656,000 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 7,153,000 | 7,294,000 | 4,539,000 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | (14,978,000) | (12,198,000) | (11,257,000) |
Income before income taxes |  |  |  |  |  |  |  |  | 51,355,000 | 59,390,000 | 61,938,000 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | (5,037,000) | (13,453,000) | (20,547,000) |
Net Income Including Noncontrolling Interest |  |  |  |  |  |  |  |  | 46,318,000 | 45,937,000 | 41,391,000 |
Less Net Income Attributable to Noncontrolling Interest, net of tax |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Net Income |  |  |  |  |  |  |  |  | 46,318,000 | 45,937,000 | 41,391,000 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 1,308,277,000 |  |  |  | 1,193,083,000 |  |  |  | 1,308,277,000 | 1,193,083,000 | 1,058,988,000 |
Capital expenditures |  |  |  |  |  |  |  |  | 125,086,000 | 176,399,000 | 77,353,000 |
MGE [Member] | Operating Segments [Member] | Gas [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 175,945,000 | 173,843,000 | 163,799,000 |
Depreciation and amortization |  |  |  |  |  |  |  |  | (11,320,000) | (10,060,000) | (9,000,000) |
Other operating expenses |  |  |  |  |  |  |  |  | (145,097,000) | (145,883,000) | (135,028,000) |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 19,528,000 | 17,900,000 | 19,771,000 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 3,550,000 | 3,132,000 | 1,911,000 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | (4,237,000) | (3,692,000) | (3,234,000) |
Income before income taxes |  |  |  |  |  |  |  |  | 18,841,000 | 17,340,000 | 18,448,000 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | (4,753,000) | (4,474,000) | (7,303,000) |
Net Income Including Noncontrolling Interest |  |  |  |  |  |  |  |  | 14,088,000 | 12,866,000 | 11,145,000 |
Less Net Income Attributable to Noncontrolling Interest, net of tax |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Net Income |  |  |  |  |  |  |  |  | 14,088,000 | 12,866,000 | 11,145,000 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 408,001,000 |  |  |  | 377,005,000 |  |  |  | 408,001,000 | 377,005,000 | 354,875,000 |
Capital expenditures |  |  |  |  |  |  |  |  | 36,193,000 | 30,497,000 | 26,847,000 |
MGE [Member] | Operating Segments [Member] | Non Regulated Energy [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 40,715,000 | 40,645,000 | 44,816,000 |
Depreciation and amortization |  |  |  |  |  |  |  |  | (7,487,000) | (7,427,000) | (7,417,000) |
Other operating expenses |  |  |  |  |  |  |  |  | (144,000) | (144,000) | (190,000) |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 33,084,000 | 33,074,000 | 37,209,000 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | (5,083,000) | (5,307,000) | (5,533,000) |
Income before income taxes |  |  |  |  |  |  |  |  | 28,001,000 | 27,767,000 | 31,676,000 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | (7,628,000) | (7,534,000) | 8,860,000 | [3]
Net Income Including Noncontrolling Interest |  |  |  |  |  |  |  |  | 20,373,000 | 20,233,000 | 40,536,000 |
Less Net Income Attributable to Noncontrolling Interest, net of tax |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Net Income |  |  |  |  |  |  |  |  | 20,373,000 | 20,233,000 | 40,536,000 |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | 257,954,000 |  |  |  | 265,251,000 |  |  |  | 257,954,000 | 265,251,000 | 270,334,000 |
Capital expenditures |  |  |  |  |  |  |  |  | 2,757,000 | 5,301,000 | 3,931,000 |
Effects Of The Tax Cuts And Jobs Act [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Net Deferred Income Tax Benefit Tax Cuts And Jobs Act |  |  |  |  |  |  |  |  |  |  | 21,700,000 |
MGE [Member] | Consolidation/Elimination Entries [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | (56,896,000) | (55,313,000) | (58,920,000) |
Depreciation and amortization |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Other operating expenses |  |  |  |  |  |  |  |  | 56,896,000 | 55,313,000 | 58,920,000 |
Operating Income (Loss) |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Other (deductions) income, net |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Interest (expense) income, net |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Income before income taxes |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Income tax (provision) benefit |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Net Income Including Noncontrolling Interest |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Less Net Income Attributable to Noncontrolling Interest, net of tax |  |  |  |  |  |  |  |  | (22,349,000) | (22,552,000) | (43,237,000) |
Net Income |  |  |  |  |  |  |  |  | (22,349,000) | (22,552,000) | (43,237,000) |
Segment Reporting Information Assets And Capital Expenditures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Assets | $ (755,000) |  |  |  | $ (448,000) |  |  |  | (755,000) | (448,000) | (156,000) |
Capital expenditures |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
MGE [Member] | Consolidation/Elimination Entries [Member] | Electric [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 806,000 | (289,000) | (513,000) |
MGE [Member] | Consolidation/Elimination Entries [Member] | Gas [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | 16,070,000 | 16,076,000 | 14,965,000 |
MGE [Member] | Consolidation/Elimination Entries [Member] | Non Regulated Energy [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Operating revenues |  |  |  |  |  |  |  |  | $ 40,020,000 | $ 39,526,000 | $ 44,468,000 |
[1] | In December 2017, there was a $21.7 million one-time tax impact as a result of the Tax Act.
[2] | In December 2017, there was a $20.4 million one-time tax impact as a result of the Tax Act.
[3] | In December 2017, there was a $21.7 million one-time tax impact as a result of the Tax Act.

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