Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Current Assets:
Cash and cash equivalents	$ 35,307	$ 21,302
Accounts receivable, less reserves	53,083	51,277
Other accounts receivables, less reserves	7,024	10,067
Unbilled revenues	30,481	35,833
Materials and supplies, at average cost	36,576	36,187
Fuel for electric generation, at average cost	12,651	11,521
Stored natural gas, at average cost	12,497	19,937
Prepaid taxes	14,128	18,390
Regulatory assets - current	8,030	8,522
Other current assets	12,569	14,229
Total Current Assets	222,346	227,265
Regulatory assets	38,312	36,764
Pension benefit asset	135,224	132,264
Other deferred assets and other	27,136	26,285
Property, Plant, and Equipment:
Property, plant, and equipment, net	2,213,857	2,149,138
Construction work in progress	84,215	138,208
Total Property, Plant, and Equipment	2,298,072	2,287,346
Investments	120,287	118,035
Total Assets	2,841,377	2,827,959
Current Liabilities:
Long-term debt due within one year	5,321	5,285
Accounts payable	48,016	77,466
Accrued interest and taxes	15,537	11,558
Accrued payroll related items	13,169	15,870
Regulatory liabilities - current	18,738	7,966
Other current liabilities	6,736	7,418
Total Current Liabilities	107,517	125,563
Other Credits:
Deferred income taxes	320,048	316,397
Investment tax credit - deferred	44,512	44,988
Regulatory liabilities	161,951	163,336
Accrued pension and other postretirement benefits	50,285	50,155
Asset retirement obligations	71,995	69,132
Other deferred liabilities and other	63,664	64,553
Total Other Credits	712,455	708,561
Capitalization:
Common shareholders equity	1,258,913	1,230,138
Long-term debt	762,492	763,697
Total Capitalization	2,021,405	1,993,835
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	2,841,377	2,827,959
MGE [Member]
Current Assets:
Cash and cash equivalents	25,154	16,865
Accounts receivable, less reserves	53,083	51,277
Other accounts receivables, less reserves	7,019	10,063
Unbilled revenues	30,481	35,833
Materials and supplies, at average cost	36,576	36,187
Fuel for electric generation, at average cost	12,651	11,521
Stored natural gas, at average cost	12,497	19,937
Prepaid taxes	14,100	18,359
Regulatory assets - current	8,030	8,522
Other current assets	13,051	14,740
Total Current Assets	212,642	223,304
Regulatory assets	38,312	36,764
Pension benefit asset	135,224	132,264
Other deferred assets and other	26,560	25,690
Property, Plant, and Equipment:
Property, plant, and equipment, net	2,213,885	2,149,165
Construction work in progress	84,215	138,208
Total Property, Plant, and Equipment	2,298,100	2,287,373
Total Assets	2,710,838	2,705,395
Current Liabilities:
Long-term debt due within one year	5,321	5,285
Accounts payable	47,989	77,453
Accrued interest and taxes	15,255	11,866
Accrued payroll related items	13,169	15,870
Regulatory liabilities - current	18,738	7,966
Other current liabilities	6,735	7,418
Total Current Liabilities	107,207	125,858
Other Credits:
Deferred income taxes	284,252	280,961
Investment tax credit - deferred	44,512	44,988
Regulatory liabilities	161,951	163,336
Accrued pension and other postretirement benefits	50,285	50,155
Asset retirement obligations	71,995	69,132
Other deferred liabilities and other	66,036	67,463
Total Other Credits	679,031	676,035
Capitalization:
Common shareholders equity	1,010,123	989,419
Noncontrolling interest	151,985	150,386
Total Equity	1,162,108	1,139,805
Long-term debt	762,492	763,697
Total Capitalization	1,924,600	1,903,502
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	$ 2,710,838	$ 2,705,395