Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 95,959	$ 81,384
Accounts receivable, less reserves	39,887	37,112
Other accounts receivables, less reserves	8,530	7,477
Unbilled revenues	29,846	25,008
Materials and supplies, at average cost	18,561	19,155
Fossil fuel, at average cost	9,757	13,110
Stored natural gas, at average cost	12,819	16,145
Prepaid taxes	26,636	35,252
Regulatory assets - current	6,414	9,538
Assets held for sale	14,813	0
Other current assets	12,293	10,570
Total Current Assets	275,515	254,751
Other long-term receivables	5,603	5,045
Regulatory assets	158,485	148,199
Pension and other postretirement benefit asset	2,020	0
Other deferred assets and other	1,088	1,332	[1]
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,245,269	1,217,094
Construction work in progress	36,790	26,351
Total Property, Plant, and Equipment	1,282,059	1,243,445
Investments	76,290	73,631
Total Assets	1,801,060	1,726,403	[1]
Current Liabilities:
Long-term debt due within one year	4,333	4,266
Accounts payable	47,799	40,830
Accrued interest and taxes	5,495	5,067
Accrued payroll related items	11,892	11,215
Regulatory liabilities - current	6,910	9,515
Derivative liabilities	7,620	8,343
Other current liabilities	19,456	4,910
Total Current Liabilities	103,505	84,146
Other Credits:
Deferred income taxes	383,813	360,785
Investment tax credit - deferred	947	1,050
Regulatory liabilities	22,173	20,785
Accrued pension and other postretirement benefits	74,347	75,680
Derivative liabilities	42,970	44,935
Other deferred liabilities and other	66,426	61,820
Total Other Credits	590,676	565,055
Common shareholders' equity:
Common stock	34,668	34,668
Additional paid-in capital	316,268	316,268
Retained earnings	372,950	339,165
Accumulated other comprehensive income, net of tax	202	357
Total Common Shareholders' Equity	724,088	690,458
Long-term debt	382,791	386,744	[1]
Total Capitalization	1,106,879	1,077,202
Commitments and contingencies (see Footnote 17)
Total Liabilities and Capitalization	1,801,060	1,726,403	[1]
MGE [Member]
Current Assets:
Cash and cash equivalents	10,768	26,760
Accounts receivable, less reserves	39,887	37,112
Affiliate receivables	539	542
Other accounts receivables, less reserves	6,363	7,390
Unbilled revenues	29,846	25,008
Materials and supplies, at average cost	18,561	19,155
Fossil fuel, at average cost	9,757	13,110
Stored natural gas, at average cost	12,819	16,145
Prepaid taxes	25,798	34,279
Regulatory assets - current	6,414	9,538
Assets held for sale	14,813	0
Other current assets	12,268	10,544
Total Current Assets	187,833	199,583
Affiliate receivable long-term	4,236	4,766
Regulatory assets	158,485	148,199
Pension and other postretirement benefit asset	2,020	0
Other deferred assets and other	4,353	4,216	[1]
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,244,648	1,216,415
Construction work in progress	36,790	26,351
Total Property, Plant, and Equipment	1,281,438	1,242,766
Investments	487	69,984
Total Assets	1,638,852	1,669,514	[1]
Current Liabilities:
Long-term debt due within one year	4,333	4,266
Accounts payable	47,790	40,742
Accrued interest and taxes	5,440	5,021
Accrued payroll related items	11,892	11,215
Regulatory liabilities - current	6,910	9,515
Derivative liabilities	7,620	8,343
Other current liabilities	19,347	4,791
Total Current Liabilities	103,332	83,893
Other Credits:
Deferred income taxes	343,117	352,626
Investment tax credit - deferred	947	1,050
Regulatory liabilities	22,173	20,785
Accrued pension and other postretirement benefits	74,347	75,680
Derivative liabilities	42,970	44,935
Other deferred liabilities and other	66,426	61,817
Total Other Credits	549,980	556,893
Common shareholders' equity:
Common stock	17,348	17,348
Additional paid-in capital	192,417	192,417
Retained earnings	277,300	291,888
Accumulated other comprehensive income, net of tax	19	23
Total Common Shareholders' Equity	487,084	501,676
Noncontrolling interest	115,665	140,308
Total Equity	602,749	641,984
Long-term debt	382,791	386,744	[1]
Total Capitalization	985,540	1,028,728
Commitments and contingencies (see Footnote 17)
Total Liabilities and Capitalization	$ 1,638,852	$ 1,669,514	[1]

[1] Reflects retrospective application of new accounting pronouncement. See Footnote 19 for additional information.