Schedule of U.S. Federal, State and Foreign Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S. federal	$ 146.7	$ 183.4	$ 161.4
State, Current	29.0	27.2	25.5
Foreign, Current	11.2	11.4	14.1
Current income tax expense (benefit)	186.9	222.0	201.0
U.S. federal, Deferred	(235.0)	19.2	22.8
State, Deferred	3.8	4.1	3.3
Foreign, Deferred	(6.4)	1.6	(2.1)
Deferred income tax expense (benefit)	(237.6)	24.9	24.0
Recorded tax expense	$ (50.7)	$ 246.9	$ 225.0