Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current Assets:
Cash and cash equivalents	$ 111,585	$ 81,384
Accounts receivable, less reserves	40,007	37,112
Other accounts receivables, less reserves	6,885	7,477
Unbilled revenues	13,885	25,008
Materials and supplies, at average cost	20,004	19,155
Fossil fuel, at average cost	9,113	13,110
Stored natural gas, at average cost	14,886	16,145
Prepaid taxes	12,617	35,252
Regulatory assets - current	7,207	9,538
Other current assets	13,115	10,570
Total Current Assets	249,304	254,751
Regulatory assets	146,305	148,199
Other deferred assets and other	6,361	6,377
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,243,081	1,217,094
Construction work in progress	38,290	26,351
Total Property, Plant, and Equipment	1,281,371	1,243,445
Investments	76,731	73,631
Total Assets	1,760,072	1,726,403
Current Liabilities:
Long-term debt due within one year	4,333	4,266
Accounts payable	49,961	40,830
Accrued interest and taxes	4,538	5,067
Accrued payroll related items	9,783	11,215
Regulatory liabilities - current	3,564	9,515
Derivative liabilities	8,030	8,343
Other current liabilities	5,950	4,910
Total Current Liabilities	86,159	84,146
Other Credits:
Deferred income taxes	376,194	360,785
Investment tax credit - deferred	973	1,050
Regulatory liabilities	21,959	20,785
Accrued pension and other postretirement benefits	61,825	75,680
Derivative liabilities	42,460	44,935
Other deferred liabilities and other	66,450	61,820
Total Other Credits	569,861	565,055
Capitalization:
Common shareholders equity	720,258	690,458
Long-term debt	383,794	386,744
Total Capitalization	1,104,052	1,077,202
Commitments and contingencies (see Footnote 7)
Total Liabilities and Capitalization	1,760,072	1,726,403
MGE [Member]
Current Assets:
Cash and cash equivalents	31,558	26,760
Accounts receivable, less reserves	40,007	37,112
Affiliate receivables	565	542
Other accounts receivables, less reserves	6,816	7,390
Unbilled revenues	13,885	25,008
Materials and supplies, at average cost	20,004	19,155
Fossil fuel, at average cost	9,113	13,110
Stored natural gas, at average cost	14,886	16,145
Prepaid taxes	12,793	34,279
Regulatory assets - current	7,207	9,538
Other current assets	13,082	10,544
Total Current Assets	169,916	199,583
Affiliate receivable long-term	4,369	4,766
Regulatory assets	146,305	148,199
Other deferred assets and other	4,100	4,216
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,242,459	1,216,415
Construction work in progress	38,290	26,351
Total Property, Plant, and Equipment	1,280,749	1,242,766
Investments	47,259	69,984
Total Assets	1,652,698	1,669,514
Current Liabilities:
Long-term debt due within one year	4,333	4,266
Accounts payable	49,949	40,742
Accrued interest and taxes	5,710	5,021
Accrued payroll related items	9,783	11,215
Regulatory liabilities - current	3,564	9,515
Derivative liabilities	8,030	8,343
Other current liabilities	5,901	4,791
Total Current Liabilities	87,270	83,893
Other Credits:
Deferred income taxes	367,066	352,626
Investment tax credit - deferred	973	1,050
Regulatory liabilities	21,959	20,785
Accrued pension and other postretirement benefits	61,825	75,680
Derivative liabilities	42,460	44,935
Other deferred liabilities and other	66,450	61,817
Total Other Credits	560,733	556,893
Capitalization:
Common shareholders equity	504,695	501,676
Noncontrolling interest	116,206	140,308
Total Equity	620,901	641,984
Long-term debt	383,794	386,744
Total Capitalization	1,004,695	1,028,728
Commitments and contingencies (see Footnote 7)
Total Liabilities and Capitalization	$ 1,652,698	$ 1,669,514