Commitments and Contingencies (Details-1) $ in Thousands	Dec. 31, 2018 USD ($) Turbines MW
Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase obligation due in next twelve months	$ 95,479
Purchase obligation due in second year	60,155
Purchase obligation due in third year	53,336
Purchase obligation due in fourth year	39,280
Purchase obligation due in fifth year	29,319
Purchase obligation due thereafter	$ 75,119
Saratoga Wind
Saratoga Capacity (MW) | MW	66
Saratoga Turbines | Turbines	33
Saratoga Wind Project Costs	$ 95,800
Coal [Member]
Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase obligation due in next twelve months	25,167	[1]
Purchase obligation due in second year	8,213	[1]
Purchase obligation due in third year	828	[1]
Purchase obligation due in fourth year	0	[1]
Purchase obligation due in fifth year	0	[1]
Purchase obligation due thereafter	0	[1]
Natural Gas, Transportation and Storage [Member]
Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase obligation due in next twelve months	21,051	[2]
Purchase obligation due in second year	20,853	[2]
Purchase obligation due in third year	20,853	[2]
Purchase obligation due in fourth year	20,853	[2]
Purchase obligation due in fifth year	20,853	[2]
Purchase obligation due thereafter	53,361	[2]
Natural Gas, Supply [Member]
Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase obligation due in next twelve months	15,423	[3]
Purchase obligation due in second year	0	[3]
Purchase obligation due in third year	0	[3]
Purchase obligation due in fourth year	0	[3]
Purchase obligation due in fifth year	0	[3]
Purchase obligation due thereafter	0	[3]
Purchase Power [Member]
Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase obligation due in next twelve months	27,577	[4]
Purchase obligation due in second year	28,082	[4]
Purchase obligation due in third year	28,675	[4]
Purchase obligation due in fourth year	15,533	[4]
Purchase obligation due in fifth year	5,641	[4]
Purchase obligation due thereafter	21,751	[4]
Other [Member]
Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase obligation due in next twelve months	6,261
Purchase obligation due in second year	3,007
Purchase obligation due in third year	2,980
Purchase obligation due in fourth year	2,894
Purchase obligation due in fifth year	2,825
Purchase obligation due thereafter	$ 7

[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] MGE's natural gas transportation and storage contracts require fixed monthly payments for firm supply pipeline transportation and storage capacity. The pricing components of the fixed monthly payments for the transportation and storage contracts are established by FERC but may be subject to change.

[3] These commitments include market-based pricing.

[4] MGE has several purchase power agreements to help meet futu re electric supply requirements .