Investment in ATC and ATC Holdco (Tables)

9 Months Ended

Sep. 30, 2025

Equity Method Investments and Joint Ventures [Abstract]

Equity Method Investments Financial Data

MGE Transco recorded the following amounts related to its investment in ATC:

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
(In thousands)	2025		2024		2025		2024
Equity earnings from investment in ATC	$	3,224	$	2,868	$	9,280	$	8,338
Dividends received from ATC		2,403		2,176		8,035		6,414
Capital contributions to ATC		3,214		894		8,385		2,679

ATC's summarized financial data is as follows:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
(In thousands)	2025			2024			2025			2024
Operating revenues	$	245,104		$	221,434		$	721,260		$	651,584
Operating expenses		(116,919	)		(110,043	)		(351,228	)		(324,082	)
Other income, net		188			355			821			898
Interest expense, net		(41,593	)		(36,838	)		(124,040	)		(108,296	)
Earnings before members' income taxes	$	86,780		$	74,908		$	246,813		$	220,104