Commitments and Contingencies (Details-3) (Purchase Power [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2014
Purchase Power [Member]
Operating expense purchase contracts [Abstract]
Purchase obligation, 2014	$ 50,542	[1]
Purchase obligation, 2015	49,072	[1]
Purchase obligation, 2016	49,743	[1]
Purchase obligation, 2017	50,243	[1]
Purchase obligation, 2018	$ 51,265	[1]

[1] MGE has several purchase power agreements to help meet future electric supply requirements. Management expects to recover these costs in future customer rates.