Investment in ATC and ATC Holdco (Tables)

9 Months Ended

Sep. 30, 2017

Equity Method Investments and Joint Ventures [Abstract]

Equity Method Investments Financial Data

MGE Transco and MGEE Transco have accounted for their investment in ATC and ATC Holdco, respectively, under the equity method of accounting.Equity earnings from investments are recorded as "Other income" on MGE Energy's consolidated statements of income. For the three and nine months endedSeptember 30,2017 and 2016, MGE Transco recorded the following:

		Three Months Ended				Nine Months Ended
		September 30,				September 30,
(In thousands)		2017		2016		2017		2016
Equity earnings from investment in ATC	$	2,338	$	2,023	$	7,432	$	6,023
Dividends from ATC(a)		2,070		1,486		4,070		4,214
Capital contributions to ATC		710		888		3,018		1,598

(a)As of December 31, 2016, MGE Transco recorded a $2.1 million receivable from ATC for a cash dividend received in January 2017.

ATC's summarized financial data for the three and nine months endedSeptember 30,2017 and 2016, is as follows:

		Three Months Ended				Nine Months Ended
		September 30,				September 30,
(In thousands)		2017		2016		2017		2016
Operating revenues	$	171,123	$	158,126	$	522,402	$	476,591
Operating expenses		(85,063)		(80,271)		(250,116)		(241,034)
Other income, net		796		1,128		1,615		2,563
Interest expense, net		(28,273)		(24,624)		(81,188)		(73,714)
Earnings before members' income taxes	$	58,583	$	54,359	$	192,713	$	164,406