Taxes (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Tax Disclosure [Line Items]
Effective income tax rate	36.50%	37.30%	36.70%	36.90%
MGE [Member]
Income Tax Disclosure [Line Items]
Effective income tax rate	36.50%	37.20%	36.70%	36.90%