Segment Information (Tables)

9 Months Ended

Sep. 30, 2021

Segment Reporting [Abstract]

Segment Information

(In thousands)			Nonregulated	Transmission	All	Consolidation/	Consolidated
MGE Energy	Electric	Gas	Energy	Investment	Others	Elimination	Total
Three Months Ended September 30, 2021
Operating revenues from external    customers	$121,639	$24,020	$214	$—	$—	$—	$145,873
Interdepartmental revenues	89	6,689	10,224	—	—	(17,002)	—
Total operating revenues	121,728	30,709	10,438	—	—	(17,002)	145,873
Equity in earnings of investments	—	—	—	2,532	—	—	2,532
Net income (loss)	27,833	(218)	5,386	1,842	74	—	34,917
Three Months Ended September 30, 2020
Operating revenues from external    customers	$116,354	$18,643	$214	$—	$—	$—	$135,211
Interdepartmental revenues	209	3,494	10,102	—	—	(13,805)	—
Total operating revenues	116,563	22,137	10,316	—	—	(13,805)	135,211
Equity in earnings of investments	—	—	—	2,353	—	—	2,353
Net income (loss)	24,761	221	5,251	1,710	(149)	—	31,794
Nine Months Ended September 30, 2021
Operating revenues from external    customers	$324,110	$119,944	$464	$—	$—	$—	$444,518
Interdepartmental revenues	316	14,377	30,595	—	—	(45,288)	—
Total operating revenues	324,426	134,321	31,059	—	—	(45,288)	444,518
Equity in earnings of investments	—	—	—	7,440	—	—	7,440
Net income (loss)	59,979	11,615	15,935	5,413	(241)	—	92,701
Nine Months Ended September 30, 2020
Operating revenues from external    customers	$303,090	$98,568	$466	$—	$—	$—	$402,124
Interdepartmental revenues	584	9,300	30,248	—	—	(40,132)	—
Total operating revenues	303,674	107,868	30,714	—	—	(40,132)	402,124
Equity in earnings of investments	—	—	—	7,780	—	—	7,780
Net income (loss)	46,439	9,216	15,536	5,659	(228)	—	76,622

(In thousands)			Nonregulated	Consolidation/	Consolidated
MGE	Electric	Gas	Energy	Elimination	Total
Three Months Ended September 30, 2021
Operating revenues from external    customers	$121,639	$24,020	$214	$—	$145,873
Interdepartmental revenues	89	6,689	10,224	(17,002)	—
Total operating revenues	121,728	30,709	10,438	(17,002)	145,873
Net income (loss) attributable to MGE	27,833	(218)	5,386	(5,627)	27,374
Three Months Ended September 30, 2020
Operating revenues from external    customers	$116,354	$18,643	$214	$—	$135,211
Interdepartmental revenues	209	3,494	10,102	(13,805)	—
Total operating revenues	116,563	22,137	10,316	(13,805)	135,211
Net income attributable to MGE	24,761	221	5,251	(5,493)	24,740
Nine Months Ended September 30, 2021
Operating revenues from external    customers	$324,110	$119,944	$464	$—	$444,518
Interdepartmental revenues	316	14,377	30,595	(45,288)	—
Total operating revenues	324,426	134,321	31,059	(45,288)	444,518
Net income attributable to MGE	59,979	11,615	15,935	(16,755)	70,774
Nine Months Ended September 30, 2020
Operating revenues from external    customers	$303,090	$98,568	$466	$—	$402,124
Interdepartmental revenues	584	9,300	30,248	(40,132)	—
Total operating revenues	303,674	107,868	30,714	(40,132)	402,124
Net income attributable to MGE	46,439	9,216	15,536	(16,754)	54,437