Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 16,270	$ 11,140
Accounts receivable, less reserves	42,962	46,734
Other accounts receivables, less reserves	16,297	15,618
Unbilled revenues	27,856	33,181
Materials and supplies, at average cost	35,454	33,385
Fuel for electric generation, at average cost	13,190	13,423
Stored natural gas, at average cost	21,960	25,840
Prepaid taxes	17,929	22,310
Regulatory assets - current	16,032	20,979
Other current assets	14,280	15,587
Total Current Assets	222,230	238,197
Regulatory assets	66,376	81,589
Pension benefit asset	99,021	93,896
Other deferred assets and other	20,910	20,741
Property, Plant, and Equipment:
Property, plant, and equipment, net	2,073,061	2,018,121
Construction work in progress	128,232	110,091
Total Property, Plant, and Equipment	2,201,293	2,128,212
Investments	114,812	112,823
Total Assets	2,724,642	2,675,458
Current Liabilities:
Long-term debt due within one year	5,215	5,146
Short-term debt	59,800	38,000
Accounts payable	49,834	65,451
Accrued interest and taxes	10,234	9,372
Accrued payroll related items	12,560	15,888
Regulatory liabilities - current	21,803	15,296
Other current liabilities	8,631	8,003
Total Current Liabilities	168,077	157,156
Other Credits:
Deferred income taxes	287,160	279,029
Investment tax credit - deferred	45,940	46,892
Regulatory liabilities	150,122	162,316
Accrued pension and other postretirement benefits	55,634	55,058
Asset Retirement Obligations, Noncurrent	71,724	54,430
Other deferred liabilities and other	61,896	61,682
Total Other Credits	672,476	659,407
Capitalization:
Common shareholders equity	1,167,628	1,140,073
Long-term debt	716,461	718,822
Total Capitalization	1,884,089	1,858,895
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	2,724,642	2,675,458
MGE [Member]
Current Assets:
Cash and cash equivalents	3,867	2,819
Accounts receivable, less reserves	42,962	46,734
Other accounts receivables, less reserves	16,294	15,616
Unbilled revenues	27,856	33,181
Materials and supplies, at average cost	35,454	33,385
Fuel for electric generation, at average cost	13,190	13,423
Stored natural gas, at average cost	21,960	25,840
Prepaid taxes	18,012	22,338
Regulatory assets - current	16,032	20,979
Other current assets	14,714	16,088
Total Current Assets	210,341	230,403
Regulatory assets	66,376	81,589
Pension benefit asset	99,021	93,896
Other deferred assets and other	20,584	20,780
Property, Plant, and Equipment:
Property, plant, and equipment, net	2,073,089	2,018,149
Construction work in progress	128,232	110,091
Total Property, Plant, and Equipment	2,201,321	2,128,240
Investments	67	60
Total Assets	2,597,710	2,554,968
Current Liabilities:
Long-term debt due within one year	5,215	5,146
Short-term debt	59,800	38,000
Accounts payable	49,821	65,434
Accrued interest and taxes	9,744	9,325
Accrued payroll related items	12,560	15,888
Regulatory liabilities - current	21,803	15,296
Other current liabilities	8,631	6,502
Total Current Liabilities	167,574	155,591
Other Credits:
Deferred income taxes	252,829	244,634
Investment tax credit - deferred	45,940	46,892
Regulatory liabilities	150,122	162,316
Accrued pension and other postretirement benefits	55,634	55,058
Asset Retirement Obligations, Noncurrent	71,724	54,430
Other deferred liabilities and other	64,216	63,969
Total Other Credits	640,465	627,299
Capitalization:
Common shareholders equity	922,316	903,725
Noncontrolling interest	150,894	149,531
Total Equity	1,073,210	1,053,256
Long-term debt	716,461	718,822
Total Capitalization	1,789,671	1,772,078
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	$ 2,597,710	$ 2,554,968