Equity and Financing Arrangements	9 Months Ended
Sep. 30, 2017
Equity and Financing Arrangements Disclosure [Abstract]
Equity and Financing Arrangements	Equity and Financing Arrangements - MGE Energy. a. Common Stock. MGE Energy sells shares of its common stock through its Stock Plan. Those shares may be newly issued shares or shares that MGE Energy has purchased in the open market for resale to 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. For both the three and nine months ended September 30, 2017 and 2016, MGE Energy did not issue any new shares of common stock under the Stock Plan. b. Dilutive Shares Calculation. MGE Energy does not have any stock option or stock award programs or any dilutive securities. c. Long-term Debt - MGE Energy and MGE. On January 13, 2017, MGE issued $40 million of 3.76% senior unsecured notes due January 15, 2052. MGE used the net proceeds from the sale of senior notes to refinance $30 million of medium-term notes, which matured in January 2017, and assist with the financing of additional capital expenditures. The long-term debt carries an interest rate of 3.76% per annum over its 35-year term. The covenants of this debt are substantially consistent with MGE's existing unsecured long-term debt. On October 2, 2017, MGE issued $30 million of 3.11% senior unsecured notes due October 1, 2027. MGE will use the net proceeds from the sale of senior notes to cover capital expenditures and other corporate obligations. The long-term debt carries an interest rate of 3.11% per annum over its 10-year term. The covenants of this debt are substantially consistent with MGE’s existing unsecured long-term debt.

Equity and Financing Arrangements

9 Months Ended

Sep. 30, 2017

Equity and Financing Arrangements Disclosure [Abstract]

Equity and Financing Arrangements - MGE Energy.

a. Common Stock.

MGE Energy sells shares of its common stock through its Stock Plan. Those shares may be newly issued shares or shares that MGE Energy has purchased in the open market for resale to 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. For both the three and nine months ended September 30, 2017 and 2016, MGE Energy did not issue any new shares of common stock under the Stock Plan.

b. Dilutive Shares Calculation.

MGE Energy does not have any stock option or stock award programs or any dilutive securities.

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

On January 13, 2017, MGE issued $40 million of 3.76% senior unsecured notes due January 15, 2052. MGE used the net proceeds from the sale of senior notes to refinance $30 million of medium-term notes, which matured in January 2017, and assist with the financing of additional capital expenditures. The long-term debt carries an interest rate of 3.76% per annum over its 35-year term. The covenants of this debt are substantially consistent with MGE's existing unsecured long-term debt.

On October 2, 2017, MGE issued $30 million of 3.11% senior unsecured notes due October 1, 2027. MGE will use the net proceeds from the sale of senior notes to cover capital expenditures and other corporate obligations. The long-term debt carries an interest rate of 3.11% per annum over its 10-year term. The covenants of this debt are substantially consistent with MGE’s existing unsecured long-term debt.