Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents	$ 94,267	$ 65,755
Accounts receivable, less reserves	35,507	41,614
Other accounts receivables, less reserves	6,549	7,610
Unbilled revenues	21,252	31,262
Materials and supplies, at average cost	19,258	17,121
Fossil fuel	14,195	8,098
Stored natural gas, at average cost	16,998	21,036
Prepaid taxes	14,507	38,910
Regulatory assets - current	9,331	8,360
Deferred income taxes - current	0	3,482
Other current assets	9,916	10,711
Total Current Assets	241,780	253,959
Regulatory assets	155,469	156,823
Other deferred assets and other	10,028	7,018
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,207,520	1,189,077
Construction work in progress	25,015	19,029
Total Property, Plant, and Equipment	1,232,535	1,208,106
Investments	74,016	71,760
Total Assets	1,713,828	1,697,666
Current Liabilities:
Long-term debt due within one year	4,245	4,182
Short-term debt	0	7,000
Accounts payable	35,854	41,655
Accrued interest and taxes	3,996	5,086
Accrued payroll related items	10,141	11,241
Deferred income taxes	945	0
Regulatory liabilities - current	4,376	0
Derivative liabilities	8,880	6,901
Other current liabilities	5,821	13,931
Total Current Liabilities	74,258	89,996
Other Credits:
Deferred income taxes	345,127	342,045
Investment tax credit - deferred	1,094	1,223
Regulatory liabilities	24,467	22,715
Accrued pension and other postretirement benefits	78,879	90,201
Derivative liabilities	48,070	46,560
Other deferred liabilities and other	60,476	50,269
Total Other Credits	558,113	553,013
Capitalization:
Common shareholders equity	689,374	659,401
Long-term debt	392,083	395,256
Total Capitalization	$ 1,081,457	$ 1,054,657
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	$ 1,713,828	$ 1,697,666
MGE [Member]
Current Assets:
Cash and cash equivalents	41,971	4,562
Accounts receivable, less reserves	35,507	41,614
Affiliate receivables	602	7,112
Other accounts receivables, less reserves	6,490	7,524
Unbilled revenues	21,252	31,262
Materials and supplies, at average cost	19,258	17,121
Fossil fuel	14,195	8,098
Stored natural gas, at average cost	16,997	21,035
Prepaid taxes	13,418	39,103
Regulatory assets - current	9,331	8,360
Deferred income taxes - current	0	1,271
Other current assets	9,881	10,683
Total Current Assets	188,902	197,745
Affiliate receivable long-term	4,898	5,295
Regulatory assets	155,469	156,823
Other deferred assets and other	7,908	4,977
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,206,828	1,188,351
Construction work in progress	25,015	19,029
Total Property, Plant, and Equipment	1,231,843	1,207,380
Investments	70,533	68,402
Total Assets	1,659,553	1,640,622
Current Liabilities:
Long-term debt due within one year	4,245	4,182
Short-term debt	0	7,000
Accounts payable	35,847	41,654
Accrued interest and taxes	3,950	5,039
Accrued payroll related items	10,141	11,241
Deferred income taxes	946	0
Regulatory liabilities - current	4,376	0
Derivative liabilities	8,880	6,901
Other current liabilities	5,600	11,350
Total Current Liabilities	73,985	87,367
Other Credits:
Deferred income taxes	337,233	334,773
Investment tax credit - deferred	1,094	1,223
Regulatory liabilities	24,467	22,715
Accrued pension and other postretirement benefits	78,879	90,201
Derivative liabilities	48,070	46,560
Other deferred liabilities and other	60,475	50,267
Total Other Credits	550,218	545,739
Capitalization:
Common shareholders equity	506,720	486,571
Noncontrolling interest	136,547	125,689
Total Equity	643,267	612,260
Long-term debt	392,083	395,256
Total Capitalization	$ 1,035,350	$ 1,007,516
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	$ 1,659,553	$ 1,640,622