Accumulated Other Comprehensive (Loss) Income, Accumulated Other Comprehensive (Loss) Income Balances (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		$ 265.9
Before tax income (loss)		124.6		$ (71.0)		$ (118.4)
Income tax effect		18.0		(5.8)		(11.9)
Other comprehensive income (loss), net of tax		142.6	[1]	(76.8)	[1]	(130.3)
Ending balance		1,476.8		265.9
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		(342.4)	[1]	(265.6)	[1]	(135.3)
Ending balance	[1]	(199.8)		(342.4)		(265.6)
Cumulative Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		(324.2)	[1]	(248.0)	[1]	(111.7)
Before tax income (loss)		157.6		(76.2)		(136.3)
Income tax effect		0.0		0.0		0.0
Other comprehensive income (loss), net of tax		157.6	[1]	(76.2)	[1]	(136.3)
Ending balance	[1]	(166.6)		(324.2)		(248.0)
Foreign Currency Gains and (Losses) [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		88.6	[1]	75.0	[1]	42.4
Before tax income (loss)		(82.8)		21.0		56.8
Income tax effect		31.2		(7.4)		(24.2)
Other comprehensive income (loss), net of tax		(51.6)	[1]	13.6	[1]	32.6
Ending balance	[1]	37.0		88.6		75.0
Unrealized (Losses) Gains on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		(42.2)	[1]	(41.3)	[1]	(25.4)
Before tax income (loss)		20.0		(1.5)		(25.6)
Income tax effect		(7.6)		0.6		9.7
Other comprehensive income (loss), net of tax		12.4	[1]	(0.9)	[1]	(15.9)
Ending balance	[1]	(29.8)		(42.2)		(41.3)
Pension and Postretirement Benefit Plans [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance		(64.6)	[1]	(51.3)	[1]	(40.6)
Before tax income (loss)		29.8		(14.3)		(13.3)
Income tax effect		(5.6)		1.0		2.6
Other comprehensive income (loss), net of tax		24.2	[1]	(13.3)	[1]	(10.7)
Ending balance	[1]	$ (40.4)		$ (64.6)		$ (51.3)

[1] All amounts are net of tax. Amounts in parentheses indicate debits.