Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents		$ 21,302	$ 11,140
Accounts receivable, less reserves		51,277	46,734
Other accounts receivables, less reserves		10,067	15,618
Unbilled revenues		35,833	33,181
Materials and supplies, at average cost		36,187	33,385
Fuel for electric generation, at average cost		11,521	13,423
Stored natural gas, at average cost		19,937	25,840
Prepaid taxes		18,390	22,310
Regulatory asset - current		8,522	20,979
Other current assets		14,229	15,587
Total Current Assets		227,265	238,197
Regulatory assets		36,764	81,589
Pension and other postretirement benefit asset		132,264	93,896
Other deferred assets and other		26,285	20,741
Property, Plant, and Equipment:
Property, plant and equipment, net		2,149,138	2,018,121
Construction work in progress		138,208	110,091
Total Property, Plant, and Equipment		2,287,346	2,128,212
Investments		118,035	112,823
Total Assets		2,827,959	2,675,458
Current Liabilities:
Long-term debt due within one year		5,285	5,146
Short-term debt	[1]	0	38,000
Accounts payable		77,466	65,451
Accrued interest and taxes		11,558	9,372
Accrued payroll related items		15,870	15,888
Regulatory liabilities - current		7,966	15,296
Other current liabilities		7,418	8,003
Total Current Liabilities		125,563	157,156
Other Credits:
Deferred income taxes		316,397	279,029
Investment tax credit - deferred		44,988	46,892
Regulatory liabilities		163,336	162,316
Accrued pension and other postretirement benefits		50,155	55,058
Asset Retirement Obligations		69,132	54,430
Other deferred liabilities and other		64,553	61,682
Total Other Credits		708,561	659,407
Common shareholders' equity:
Common stock		36,490	36,163
Additional paid-in capital		429,515	396,750
Retained earnings		764,133	707,160
Total Common Shareholders' Equity		1,230,138	1,140,073
Long-term debt		763,697	718,822
Total Capitalization		1,993,835	1,858,895
Commitments and contingencies (see Footnote 16)
Total Liabilities and Capitalization		2,827,959	2,675,458
MGE [Member]
Current Assets:
Cash and cash equivalents		16,865	2,819
Accounts receivable, less reserves		51,277	46,734
Other accounts receivables, less reserves		10,063	15,616
Unbilled revenues		35,833	33,181
Materials and supplies, at average cost		36,187	33,385
Fuel for electric generation, at average cost		11,521	13,423
Stored natural gas, at average cost		19,937	25,840
Prepaid taxes		18,359	22,338
Regulatory asset - current		8,522	20,979
Other current assets		14,740	16,088
Total Current Assets		223,304	230,403
Regulatory assets		36,764	81,589
Pension and other postretirement benefit asset		132,264	93,896
Other deferred assets and other		25,690	20,780
Property, Plant, and Equipment:
Property, plant and equipment, net		2,149,165	2,018,149
Construction work in progress		138,208	110,091
Total Property, Plant, and Equipment		2,287,373	2,128,240
Investments		0	60
Total Assets		2,705,395	2,554,968
Current Liabilities:
Long-term debt due within one year		5,285	5,146
Short-term debt		0	38,000
Accounts payable		77,453	65,434
Accrued interest and taxes		11,866	9,325
Accrued payroll related items		15,870	15,888
Regulatory liabilities - current		7,966	15,296
Other current liabilities		7,418	6,502
Total Current Liabilities		125,858	155,591
Other Credits:
Deferred income taxes		280,961	244,634
Investment tax credit - deferred		44,988	46,892
Regulatory liabilities		163,336	162,316
Accrued pension and other postretirement benefits		50,155	55,058
Asset Retirement Obligations		69,132	54,430
Other deferred liabilities and other		67,463	63,969
Total Other Credits		676,035	627,299
Common shareholders' equity:
Common stock		17,348	17,348
Additional paid-in capital		283,667	252,917
Retained earnings		688,404	633,460
Total Common Shareholders' Equity		989,419	903,725
Noncontrolling interest		150,386	149,531
Total Equity		1,139,805	1,053,256
Long-term debt		763,697	718,822
Total Capitalization		1,903,502	1,772,078
Commitments and contingencies (see Footnote 16)
Total Liabilities and Capitalization		$ 2,705,395	$ 2,554,968

[1] MGE Energy short-term borrowings include MGE Energy and MGE lines of credit and MGE commercial paper.