Income Taxes Current and Deferred Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal U.S.	$ 215.9	$ 227.4	$ 310.8
Non-U.S.	88.7	74.6	54.3
State and local	13.3	32.7	32.8
Deferred:
Federal U.S.	(79.5)	(4.6)	(4.0)
Non-U.S.	(2.2)	(3.0)	12.7
State and local	3.5	(2.4)	(0.7)
Income tax provision	$ 239.7	$ 324.7	$ 405.9