Supplemental Cash Flow Information (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental Cash Flow Information [Abstract]
Cash paid for interest		$ 82.3	$ 78.8	$ 74.5
Cash paid for income taxes, net of refunds	[1]	228.4	244.1	231.9
Tax refunds		$ 31.9	$ 26.6	$ 13.0

[1] Refunds of $31.9, $26.6 and $13.0 were received for the years ended December 31, 2017, 2016 and 2015, respectively.