Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current Assets:
Cash and cash equivalents	$ 95,579	$ 107,952
Accounts receivable, less reserves	35,473	42,299
Other accounts receivables, less reserves	7,808	9,440
Unbilled revenues	24,031	31,400
Materials and supplies, at average cost	24,595	22,614
Fuel for electric generation, at average cost	9,451	8,256
Stored natural gas, at average cost	7,763	12,923
Prepaid taxes	16,042	26,535
Regulatory assets - current	7,462	7,888
Assets held for sale	1,392	8,817
Other current assets	12,714	12,507
Total Current Assets	242,310	290,631
Other long-term receivables	4,188	4,788
Regulatory assets	137,267	142,567
Pension and other postretirement benefit asset	11,956	7,336
Other deferred assets and other	5,379	731
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,345,255	1,283,313
Construction work in progress	75,007	58,044
Total Property, Plant, and Equipment	1,420,262	1,341,357
Investments	72,083	67,772
Total Assets	1,893,445	1,855,182
Current Liabilities:
Long-term debt due within one year	4,502	24,452
Short-term debt	28,200	4,000
Accounts payable	37,498	47,645
Accrued interest and taxes	5,350	5,602
Accrued payroll related items	10,449	12,244
Regulatory liabilities - current	9,110	5,633
Derivative liabilities	8,860	8,180
Other current liabilities	14,457	18,758
Total Current Liabilities	118,426	126,514
Other Credits:
Deferred income taxes	226,300	225,130
Investment tax credit - deferred	868	918
Regulatory liabilities	166,316	154,153
Accrued pension and other postretirement benefits	69,249	69,088
Derivative liabilities	29,890	33,990
Other deferred liabilities and other	72,120	69,041
Total Other Credits	564,743	552,320
Capitalization:
Common shareholders equity	794,178	778,187
Long-term debt	416,098	398,161
Total Capitalization	1,210,276	1,176,348
Commitments and contingencies (see Footnote 9)
Total Liabilities and Capitalization	1,893,445	1,855,182
MGE [Member]
Current Assets:
Cash and cash equivalents	3,128	5,951
Accounts receivable, less reserves	35,473	42,299
Affiliate receivables	592	668
Other accounts receivables, less reserves	6,297	6,984
Unbilled revenues	24,031	31,400
Materials and supplies, at average cost	24,595	22,614
Fuel for electric generation, at average cost	9,451	8,256
Stored natural gas, at average cost	7,763	12,923
Prepaid taxes	15,073	25,073
Regulatory assets - current	7,462	7,888
Assets held for sale	1,392	8,817
Other current assets	12,709	12,484
Total Current Assets	147,966	185,357
Affiliate receivable long-term	3,442	3,707
Regulatory assets	137,267	142,567
Pension and other postretirement benefit asset	11,956	7,336
Other deferred assets and other	7,558	3,280
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,345,283	1,283,341
Construction work in progress	75,007	58,044
Total Property, Plant, and Equipment	1,420,290	1,341,385
Investments	422	409
Total Assets	1,728,901	1,684,041
Current Liabilities:
Long-term debt due within one year	4,502	24,452
Short-term debt	28,200	4,000
Accounts payable	37,498	47,614
Accrued interest and taxes	6,551	5,558
Accrued payroll related items	10,449	12,244
Regulatory liabilities - current	9,110	5,633
Derivative liabilities	8,860	8,180
Other current liabilities	14,448	16,749
Total Current Liabilities	119,618	124,430
Other Credits:
Deferred income taxes	200,609	201,486
Investment tax credit - deferred	868	918
Regulatory liabilities	166,316	154,153
Accrued pension and other postretirement benefits	69,249	69,088
Derivative liabilities	29,890	33,990
Other deferred liabilities and other	72,120	69,041
Total Other Credits	539,052	528,676
Capitalization:
Common shareholders equity	515,420	491,872
Noncontrolling interest	138,713	140,902
Total Equity	654,133	632,774
Long-term debt	416,098	398,161
Total Capitalization	1,070,231	1,030,935
Commitments and contingencies (see Footnote 9)
Total Liabilities and Capitalization	$ 1,728,901	$ 1,684,041