Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 14,875	$ 11,140
Accounts receivable, less reserves	44,626	46,734
Other accounts receivables, less reserves	14,744	15,618
Unbilled revenues	25,925	33,181
Materials and supplies, at average cost	34,993	33,385
Fuel for electric generation, at average cost	11,295	13,423
Stored natural gas, at average cost	23,126	25,840
Prepaid taxes	13,674	22,310
Regulatory assets - current	12,291	20,979
Other current assets	14,776	15,587
Total Current Assets	210,325	238,197
Regulatory assets	66,186	81,589
Pension benefit asset	101,584	93,896
Other deferred assets and other	22,273	20,741
Property, Plant, and Equipment:
Property, plant, and equipment, net	2,077,104	2,018,121
Construction work in progress	155,448	110,091
Total Property, Plant, and Equipment	2,232,552	2,128,212
Investments	116,405	112,823
Total Assets	2,749,325	2,675,458
Current Liabilities:
Long-term debt due within one year	5,250	5,146
Short-term debt	48,500	38,000
Accounts payable	45,710	65,451
Accrued interest and taxes	10,479	9,372
Accrued payroll related items	14,739	15,888
Regulatory liabilities - current	16,465	15,296
Other current liabilities	8,462	8,003
Total Current Liabilities	149,605	157,156
Other Credits:
Deferred income taxes	299,728	279,029
Investment tax credit - deferred	45,464	46,892
Regulatory liabilities	151,657	162,316
Accrued pension and other postretirement benefits	56,363	55,058
Asset retirement obligations	72,226	54,430
Other deferred liabilities and other	63,749	61,682
Total Other Credits	689,187	659,407
Capitalization:
Common shareholders equity	1,195,265	1,140,073
Long-term debt	715,268	718,822
Total Capitalization	1,910,533	1,858,895
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	2,749,325	2,675,458
MGE [Member]
Current Assets:
Cash and cash equivalents	3,140	2,819
Accounts receivable, less reserves	44,626	46,734
Other accounts receivables, less reserves	14,740	15,616
Unbilled revenues	25,925	33,181
Materials and supplies, at average cost	34,993	33,385
Fuel for electric generation, at average cost	11,295	13,423
Stored natural gas, at average cost	23,126	25,840
Prepaid taxes	13,614	22,338
Regulatory assets - current	12,291	20,979
Other current assets	15,243	16,088
Total Current Assets	198,993	230,403
Regulatory assets	66,186	81,589
Pension benefit asset	101,584	93,896
Other deferred assets and other	21,777	20,780
Property, Plant, and Equipment:
Property, plant, and equipment, net	2,077,132	2,018,149
Construction work in progress	155,448	110,091
Total Property, Plant, and Equipment	2,232,580	2,128,240
Investments	0	60
Total Assets	2,621,120	2,554,968
Current Liabilities:
Long-term debt due within one year	5,250	5,146
Short-term debt	48,500	38,000
Accounts payable	45,695	65,434
Accrued interest and taxes	9,685	9,325
Accrued payroll related items	14,739	15,888
Regulatory liabilities - current	16,465	15,296
Other current liabilities	8,495	6,502
Total Current Liabilities	148,829	155,591
Other Credits:
Deferred income taxes	265,549	244,634
Investment tax credit - deferred	45,464	46,892
Regulatory liabilities	151,657	162,316
Accrued pension and other postretirement benefits	56,363	55,058
Asset retirement obligations	72,226	54,430
Other deferred liabilities and other	66,444	63,969
Total Other Credits	657,703	627,299
Capitalization:
Common shareholders equity	948,649	903,725
Noncontrolling interest	150,671	149,531
Total Equity	1,099,320	1,053,256
Long-term debt	715,268	718,822
Total Capitalization	1,814,588	1,772,078
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	$ 2,621,120	$ 2,554,968