MGE Energy Inc Consolidated Statements of Common Equity (USD $) In Thousands, unless otherwise specified		Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss)/ Income [Member]
Beginning balance, value at Dec. 31, 2010		$ 525,080	$ 34,668	$ 316,268	$ 174,002	$ 142
Beginning balance, shares at Dec. 31, 2010			34,668
Increase (Decrease) in Common Equity [Roll Forward]
Net Income		60,928			60,928
Other comprehensive income/(loss)		(30)				(30)
Common stock dividends declared	[1]	(35,026)			(35,026)
Ending balance, value at Dec. 31, 2011		550,952	34,668	316,268	199,904	112
Ending balance, shares at Dec. 31, 2011			34,668
Increase (Decrease) in Common Equity [Roll Forward]
Net Income		64,446			64,446
Other comprehensive income/(loss)		(18)				(18)
Common stock dividends declared	[2]	(35,951)			(35,951)
Ending balance, value at Dec. 31, 2012		579,429	34,668	316,268	228,399	94
Ending balance, shares at Dec. 31, 2012			34,668
Increase (Decrease) in Common Equity [Roll Forward]
Net Income		74,905			74,905
Other comprehensive income/(loss)		283				283
Common stock dividends declared	[3]	(37,107)			(37,107)
Ending balance, value at Dec. 31, 2013		$ 617,510	$ 34,668	$ 316,268	$ 266,197	$ 377
Ending balance, shares at Dec. 31, 2013			34,668

[1] $1.01 per share

[2] $1.04 per share

[3] $1.07 per share