Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 16,507	$ 11,604
Accounts receivable, less reserves	41,025	55,407
Other accounts receivables, less reserves	15,198	11,418
Unbilled revenues	26,650	43,086
Materials and supplies, at average cost	33,757	33,465
Fuel for electric generation, at average cost	12,524	7,962
Stored natural gas, at average cost	25,601	32,848
Prepaid taxes	20,025	19,132
Regulatory assets - current	16,347	9,541
Other current assets	14,897	19,017
Total Current Assets	222,531	243,480
Regulatory assets	97,801	103,900
Pension benefit asset	72,349	68,872
Other deferred assets and other	22,326	24,365
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,903,143	1,865,352
Construction work in progress	132,980	105,748
Total Property, Plant, and Equipment	2,036,123	1,971,100
Investments	108,938	105,883
Total Assets	2,560,068	2,517,600
Current Liabilities:
Long-term debt due within one year	35,079	54,314
Short-term debt	42,000	70,500
Accounts payable	38,571	59,334
Accrued interest and taxes	8,750	7,868
Accrued payroll related items	10,337	13,064
Regulatory liabilities - current	15,831	11,925
Other current liabilities	8,831	8,057
Total Current Liabilities	159,399	225,062
Other Credits:
Deferred income taxes	266,807	252,190
Investment tax credit - deferred	47,785	48,735
Regulatory liabilities	153,549	156,988
Accrued pension and other postretirement benefits	54,179	53,607
Finance lease liabilities	17,860	17,108
Other deferred liabilities and other	96,251	96,990
Total Other Credits	636,431	625,618
Capitalization:
Common shareholders equity	1,112,584	1,081,674
Long-term debt	651,654	585,246
Total Capitalization	1,764,238	1,666,920
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	2,560,068	2,517,600
MGE [Member]
Current Assets:
Cash and cash equivalents	8,574	4,136
Accounts receivable, less reserves	41,025	55,407
Other accounts receivables, less reserves	15,195	11,416
Unbilled revenues	26,650	43,086
Materials and supplies, at average cost	33,757	33,465
Fuel for electric generation, at average cost	12,524	7,962
Stored natural gas, at average cost	25,601	32,848
Prepaid taxes	19,885	18,467
Regulatory assets - current	16,347	9,541
Other current assets	15,413	19,479
Total Current Assets	214,971	235,807
Regulatory assets	97,801	103,900
Pension benefit asset	72,349	68,872
Other deferred assets and other	22,528	24,817
Property, Plant, and Equipment:
Property, plant, and equipment, net	1,903,171	1,865,380
Construction work in progress	132,980	105,748
Total Property, Plant, and Equipment	2,036,151	1,971,128
Investments	108	115
Total Assets	2,443,908	2,404,639
Current Liabilities:
Long-term debt due within one year	35,079	54,314
Short-term debt	42,000	70,500
Accounts payable	38,501	59,317
Accrued interest and taxes	8,705	7,912
Accrued payroll related items	10,337	13,064
Regulatory liabilities - current	15,831	11,925
Other current liabilities	8,841	6,062
Total Current Liabilities	159,294	223,094
Other Credits:
Deferred income taxes	233,117	219,258
Investment tax credit - deferred	47,785	48,735
Regulatory liabilities	153,549	156,988
Accrued pension and other postretirement benefits	54,179	53,607
Finance lease liabilities	17,860	17,108
Other deferred liabilities and other	98,084	98,217
Total Other Credits	604,574	593,913
Capitalization:
Common shareholders equity	879,578	854,223
Noncontrolling interest	148,808	148,163
Total Equity	1,028,386	1,002,386
Long-term debt	651,654	585,246
Total Capitalization	1,680,040	1,587,632
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	$ 2,443,908	$ 2,404,639