Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 110,308	$ 81,384
Accounts receivable, less reserves	31,444	37,112
Other accounts receivables, less reserves	6,765	7,477
Unbilled revenues	25,653	25,008
Materials and supplies, at average cost	20,825	19,155
Fossil fuel, at average cost	9,502	13,110
Stored natural gas, at average cost	10,029	16,145
Prepaid taxes	19,831	35,252
Regulatory assets - current	7,170	9,538
Other current assets	13,402	10,570
Total Current Assets	254,929	254,751
Regulatory assets	147,157	148,199
Other deferred assets and other	6,372	6,377
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,234,587	1,217,094
Construction work in progress	32,187	26,351
Total Property, Plant, and Equipment	1,266,774	1,243,445
Investments	75,347	73,631
Total Assets	1,750,579	1,726,403
Current Liabilities:
Long-term debt due within one year	34,294	4,266
Accounts payable	46,304	40,830
Accrued interest and taxes	4,940	5,067
Accrued payroll related items	9,453	11,215
Regulatory liabilities - current	14,818	9,515
Derivative liabilities	8,650	8,343
Other current liabilities	10,099	4,910
Total Current Liabilities	128,558	84,146
Other Credits:
Deferred income taxes	370,516	360,785
Investment tax credit - deferred	999	1,050
Regulatory liabilities	22,138	20,785
Accrued pension and other postretirement benefits	63,085	75,680
Derivative liabilities	43,590	44,935
Other deferred liabilities and other	63,865	61,820
Total Other Credits	564,193	565,055
Capitalization:
Common shareholders equity	703,028	690,458
Long-term debt	354,800	386,744
Total Capitalization	1,057,828	1,077,202
Commitments and contingencies (see Footnote 7)
Total Liabilities and Capitalization	1,750,579	1,726,403
MGE [Member]
Current Assets:
Cash and cash equivalents	40,947	26,760
Accounts receivable, less reserves	31,444	37,112
Affiliate receivables	547	542
Other accounts receivables, less reserves	6,745	7,390
Unbilled revenues	25,653	25,008
Materials and supplies, at average cost	20,825	19,155
Fossil fuel, at average cost	9,502	13,110
Stored natural gas, at average cost	10,028	16,145
Prepaid taxes	18,726	34,279
Regulatory assets - current	7,170	9,538
Other current assets	13,394	10,544
Total Current Assets	184,981	199,583
Affiliate receivable long-term	4,501	4,766
Regulatory assets	147,157	148,199
Other deferred assets and other	4,178	4,216
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,233,966	1,216,415
Construction work in progress	32,187	26,351
Total Property, Plant, and Equipment	1,266,153	1,242,766
Investments	71,901	69,984
Total Assets	1,678,871	1,669,514
Current Liabilities:
Long-term debt due within one year	34,294	4,266
Accounts payable	46,304	40,742
Accrued interest and taxes	4,889	5,021
Accrued payroll related items	9,453	11,215
Regulatory liabilities - current	14,818	9,515
Derivative liabilities	8,650	8,343
Other current liabilities	9,790	4,791
Total Current Liabilities	128,198	83,893
Other Credits:
Deferred income taxes	361,807	352,626
Investment tax credit - deferred	999	1,050
Regulatory liabilities	22,138	20,785
Accrued pension and other postretirement benefits	63,085	75,680
Derivative liabilities	43,590	44,935
Other deferred liabilities and other	63,864	61,817
Total Other Credits	555,483	556,893
Capitalization:
Common shareholders equity	497,720	501,676
Noncontrolling interest	142,670	140,308
Total Equity	640,390	641,984
Long-term debt	354,800	386,744
Total Capitalization	995,190	1,028,728
Commitments and contingencies (see Footnote 7)
Total Liabilities and Capitalization	$ 1,678,871	$ 1,669,514