Equity and Financing Arrangements	6 Months Ended
Jun. 30, 2020
Equity and Financing Arrangements Disclosure [Abstract]
Equity and Financing Arrangements	Equity and Financing Arrangements. a.Common Stock - MGE Energy. MGE Energy sells shares of its common stock through its Direct Stock Purchase and Dividend Reinvestment Plan (the Stock Plan). Those shares may be newly issued shares or shares that are purchased in the open market by an independent agent for participants in the Stock Plan. All sales under the Stock Plan are covered by a shelf registration statement that MGE Energy filed with the SEC. During the three and six months ended June 30, 2020 and 2019, MGE Energy issued no new shares of common stock under the Stock Plan. In May 2020, MGE Energy issued 1.5 million shares of its common stock in an underwritten offering. MGE Energy received proceeds, net of underwriter fees and issuance costs, of $79.6 million from the issuance and sale of those shares. The net proceeds are expected to be used for general corporate purposes, including capital expenditures. b.Dilutive Shares Calculation - MGE Energy. MGE Energy has no dilutive securities issued. c.Long-term Debt - MGE Energy and MGE. In April 2020, MGE borrowed $19.3 million from the City of Madison, Wisconsin's issuance of Industrial Development Revenue Refunding Bonds (Madison Gas and Electric Company Project), Series 2020A. The bonds carry an interest rate of 2.05% per annum with interest payable semi-annually on April 1 and October 1 of each year, commencing on October 1, 2020. The bonds require their holder to tender them on April 30, 2023, at which time the bonds will either be repriced and remarketed or redeemed and retired. MGE used the proceeds to redeem at par $19.3 million of existing Industrial Development Revenue Refunding Bonds (Madison Gas and Electric Company Project), Series 2002B due October 1, 2027. The funds for the loan were provided by a purchaser of the bonds pursuant to a Bond Purchase and Covenants Agreement between that purchaser and MGE. That Agreement requires MGE to maintain a ratio of consolidated indebtedness to consolidated total capitalization not to exceed a maximum of 65%. Both consolidated indebtedness and consolidated total capitalization are to be determined in accordance with GAAP, except that amounts included within MGE's indebtedness and capitalization from "variable interest entities" are excluded. A change of control constitutes a default under the Bond Purchase Agreement. Change in control events are defined as (i) a failure by MGE Energy to hold 100% of the outstanding voting equity interest in MGE or (ii) the acquisition of beneficial ownership of 30% or more of the outstanding voting stock of MGE Energy by one person or two or more persons acting in concert. The ratio, and its calculation, and the change of control provision reflect the provisions contained in MGE’s credit agreements.

Equity and Financing Arrangements

6 Months Ended

Jun. 30, 2020

Equity and Financing Arrangements Disclosure [Abstract]

Equity and Financing Arrangements.

a.Common Stock - MGE Energy.

MGE Energy sells shares of its common stock through its Direct Stock Purchase and Dividend Reinvestment Plan (the Stock Plan). Those shares may be newly issued shares or shares that are purchased in the open market by an independent agent for participants in the Stock Plan. All sales under the Stock Plan are covered by a shelf registration statement that MGE Energy filed with the SEC. During the three and six months ended June 30, 2020 and 2019, MGE Energy issued no new shares of common stock under the Stock Plan.

In May 2020, MGE Energy issued 1.5 million shares of its common stock in an underwritten offering. MGE Energy received proceeds, net of underwriter fees and issuance costs, of $79.6 million from the issuance and sale of those shares. The net proceeds are expected to be used for general corporate purposes, including capital expenditures.

b.Dilutive Shares Calculation - MGE Energy.

MGE Energy has no dilutive securities issued.

c.Long-term Debt - MGE Energy and MGE.

In April 2020, MGE borrowed $19.3 million from the City of Madison, Wisconsin's issuance of Industrial Development Revenue Refunding Bonds (Madison Gas and Electric Company Project), Series 2020A. The bonds carry an interest rate of 2.05% per annum with interest payable semi-annually on April 1 and October 1 of each year, commencing on October 1, 2020. The bonds require their holder to tender them on April 30, 2023, at which time the bonds will either be repriced and remarketed or redeemed and retired. MGE used the proceeds to redeem at par $19.3 million of existing Industrial Development Revenue Refunding Bonds (Madison Gas and Electric Company Project), Series 2002B due October 1, 2027.

The funds for the loan were provided by a purchaser of the bonds pursuant to a Bond Purchase and Covenants Agreement between that purchaser and MGE. That Agreement requires MGE to maintain a ratio of consolidated indebtedness to consolidated total capitalization not to exceed a maximum of 65%. Both consolidated indebtedness and consolidated total capitalization are to be determined in accordance with GAAP, except that amounts included within MGE's indebtedness and capitalization from "variable interest entities" are excluded. A change of control constitutes a default under the Bond Purchase Agreement. Change in control events are defined as (i) a failure by MGE Energy to hold 100% of the outstanding voting equity interest in MGE or (ii) the acquisition of beneficial ownership of 30% or more of the outstanding voting stock of MGE Energy by one person or two or more persons acting in concert. The ratio, and its calculation, and the change of control provision reflect the provisions contained in MGE’s credit agreements.