Schedule I - Condensed Parent Company Finanical Statements (Details-Notes 1) (Line of Credit [Member], USD $)	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Credit facilities [Line Items]
Available lines of credit	$ 150,000,000	[1]	$ 115,000,000	[1]	$ 115,000,000	[1]
MGE Energy [Member] | MGE Energy $50 million unsecured commiteed revolving line of credit
Credit facilities [Line Items]
Available lines of credit	50,000,000
Line of credit, borrowings outstanding	$ 0

[1] MGE Energy short-term borrowings include MGE Energy and MGE lines of credit and MGE commercial paper.