MGE Energy Inc Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Comprehensive Income [Abstract]
Net Income	$ 14,087	$ 13,891	$ 41,804	$ 36,475
Other comprehensive income (loss), net of tax:
Unrealized gain (loss) on available-for-sale securities, net of tax	(46)	75	(39)	140
Comprehensive Income	$ 14,041	$ 13,966	$ 41,765	$ 36,615