Taxes (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Effective Tax Rate Reconciliation

The consolidated income tax provision differs from the amount computed by applying the statutory federal income tax rate to income before income taxes, as follows:

	MGE Energy		MGE
Three Months Ended March 31,	2018	2017	2018	2017
Statutory federal income tax rate	21.0 %	35.0 %	21.0 %	35.0 %
State income taxes, net of federal benefit	6.4 %	5.3 %	6.0 %	5.1 %
Amortized investment tax credits	(0.1)%	(0.1)%	(0.1)%	(0.1)%
Credit for electricity from wind energy	(0.5)%	(1.8)%	(0.5)%	(2.0)%
Domestic manufacturing deduction	-%	(1.3)%	-%	(1.4)%
AFUDC equity, net	(0.4)%	(0.2)%	(0.4)%	(0.2)%
Amortization of utility excess deferred tax - tax reform(a)	(1.8)%	-%	(2.0)%	-%
Other, net, individually insignificant	(0.4)%	(0.2)%	(0.6)%	(0.2)%
Effective income tax rate	24.2 %	36.7 %	23.4 %	36.2 %

(a)Included are impacts of the Tax Act for the regulated utility for excess deferred taxes recognized using a normalization method of accounting.