MGE Energy Inc Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Comprehensive Income [Abstract]
Net Income	$ 28,354	$ 23,329	$ 60,111	$ 65,133
Other comprehensive income (loss), net of tax:
Unrealized (loss) gain on available-for-sale securities, net of tax	(85)	95	(180)	56
Comprehensive Income	$ 28,269	$ 23,424	$ 59,931	$ 65,189