Share-Based Compensation (Tables) - Performance Units [Member]

12 Months Ended

Dec. 31, 2019

Director Incentive Agreement [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Performance Unit Graded Vesting Schedule

Units granted under the Director Incentive Plan are subject to a three-year vesting schedule. Grants since January 1, 2018, under this plan are as follows:

Grant Date	MGE Energy Units Granted
January 17, 2020	5,048
January 18, 2019	5,175
March 1, 2018	1,106
January 19, 2018	4,704

Performance Unit Plan [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Performance Unit Graded Vesting Schedule

Units granted under the Performance Unit Plan are subject to a five-year vesting schedule. Grants since January 1, 2016, under this plan are as follows:

Grant Date	MGE Energy Units Granted
February 15, 2019	17,022
February 16, 2018	17,830
March 1, 2017	14,704
February 19, 2016	19,055