Schedule I - Condensed Parent Company Finanical Statements (Details-Comprehensive Income Statement) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Expenses:
Other operations and maintenance	$ 199,316	$ 186,430	$ 193,322
Total Operating Expenses	489,290	428,636	457,945
Operating Income	117,294	109,997	110,910
Equity earnings of investments	9,270	10,221	9,889
Income before income taxes	109,876	111,841	106,658
Income tax provision	(4,115)	(19,423)	(19,784)
Net Income	105,761	92,418	86,874
MGE Energy [Member]
Operating Expenses:
Other operations and maintenance	711	882	815
Total Operating Expenses	711	882	815
Operating Income	(711)	(882)	(815)
Equity earnings of investments	107,883	92,922	87,728
Other income/(loss), net	(2,163)	94	(1,500)
Interest income, net	5	78	1,224
Income before income taxes	105,014	92,212	86,637
Income tax provision	747	206	237
Net Income	$ 105,761	$ 92,418	$ 86,874