Commitments and Contingencies (Details-1) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($) Turbines MW
Operating expense purchase contracts [Abstract]
Purchase obligation, 2018	$ 27,735
Purchase obligation, 2019	31,778
Purchase obligation, 2020	8,065
Purchase obligation, 2021	2,277
Purchase obligation, 2022	2,286
Purchase obligation, Thereafter	4,931
Coal [Member]
Operating expense purchase contracts [Abstract]
Purchase obligation, 2018	13,301	[1]
Purchase obligation, 2019	17,831	[1]
Purchase obligation, 2020	5,297	[1]
Purchase obligation, 2021	0	[1]
Purchase obligation, 2022	0	[1]
Purchase obligation, Thereafter	0	[1]
Natual Gas, Supply [Member]
Operating expense purchase contracts [Abstract]
Purchase obligation, 2018	11,624	[2]
Purchase obligation, 2019	12,587	[2]
Purchase obligation, 2020	0	[2]
Purchase obligation, 2021	0	[2]
Purchase obligation, 2022	0	[2]
Purchase obligation, Thereafter	0	[2]
Saratoga Wind [Member]
Operating expense purchase contracts [Abstract]
Purchase obligation, 2018	1,038	[3]
Purchase obligation, 2019	858	[3]
Purchase obligation, 2020	2,266	[3]
Purchase obligation, 2021	1,775	[3]
Purchase obligation, 2022	1,784	[3]
Purchase obligation, Thereafter	$ 4,429	[3]
Saratoga Wind
Saratoga Capacity (MW) | MW	66
Saratoga Turbines | Turbines	33
Projected Saratoga Wind Project Costs	$ 108,000
Saratoga Wind Project Costs Year to Date	$ 42,600
Saratoga Wind [Member] | Public Service Commission of Wisconsin [Member]
Allowance for Funds Used During Construction
Authorized AFUDC Rate	100.00%
Other [Member]
Operating expense purchase contracts [Abstract]
Purchase obligation, 2018	$ 1,772
Purchase obligation, 2019	502
Purchase obligation, 2020	502
Purchase obligation, 2021	502
Purchase obligation, 2022	502
Purchase obligation, Thereafter	$ 502

[1] Total coal commitments for the Columbia and Elm Road Units, including transportation. Fuel procurement for MGE's jointly owned Columbia and Elm Road Units is handled by WPL and WEPCO, respectively, who are the operators of those facilities.

[2] These commitments include market-based pricing.

[3] In December 2017, the PSCW authorized construction of a 66MW wind farm, consisting of 33 turbines, located near Saratoga, Iowa. MGE received specific approval to recover 100% AFUDC on the project. As of June 30, 2018, MGE has incurred $ 42.6 million of capital expenditures. Construction of the project is expected to be completed by the end of 2018, with an estimated capital cost of $108 million.