Joint Plant Ownership	9 Months Ended
Sep. 30, 2019
Regulated Operations [Abstract]
Joint Plant Ownership	Joint Plant Ownership - MGE Energy and MGE. a. Two Creeks. In May 2019, MGE acquired a 33% ownership interest in a 150 MW solar generation array in the Town of Two Creeks and the City of Two Rivers in Manitowoc and Kewaunee Counties, Wisconsin. MGE's sole principal asset will be the 33% undivided ownership interest in the solar generation facility, which is being constructed. The estimated share of capital costs for MGE's ownership interest is approximately $65 million (excluding capitalized interest). As of September 30, 2019, $42.1 million (excluding capitalized interest) related to this project is reflected in "Construction work in progress" on the consolidated balance sheets. The project is anticipated to be completed by the end of 2020. b. Badger Hollow. In July 2019, MGE acquired a 33% ownership interest in a 150 MW solar generation array in southwestern Wisconsin in Iowa County, near the villages of Montfort and Cobb. MGE's sole principal asset will be the 33% undivided ownership interest in the solar generation facility which is being constructed. The estimated share of capital costs for MGE's ownership interest is approximately $65 million (excluding capitalized interest). As of September 30, 2019, $10.0 million (excluding capitalized interest) related to this project is reflected in "Construction work in progress" on the consolidated balance sheets. The project is anticipated to be completed by the end of 2020.

Joint Plant Ownership

9 Months Ended

Sep. 30, 2019

Joint Plant Ownership - MGE Energy and MGE.

a. Two Creeks.

In May 2019, MGE acquired a 33% ownership interest in a 150 MW solar generation array in the Town of Two Creeks and the City of Two Rivers in Manitowoc and Kewaunee Counties, Wisconsin. MGE's sole principal asset will be the 33% undivided ownership interest in the solar generation facility, which is being constructed. The estimated share of capital costs for MGE's ownership interest is approximately $65 million (excluding capitalized interest).

As of September 30, 2019, $42.1 million (excluding capitalized interest) related to this project is reflected in "Construction work in progress" on the consolidated balance sheets. The project is anticipated to be completed by the end of 2020.

b. Badger Hollow.

In July 2019, MGE acquired a 33% ownership interest in a 150 MW solar generation array in southwestern Wisconsin in Iowa County, near the villages of Montfort and Cobb. MGE's sole principal asset will be the 33% undivided ownership interest in the solar generation facility which is being constructed. The estimated share of capital costs for MGE's ownership interest is approximately $65 million (excluding capitalized interest).

As of September 30, 2019, $10.0 million (excluding capitalized interest) related to this project is reflected in "Construction work in progress" on the consolidated balance sheets. The project is anticipated to be completed by the end of 2020.