Equity - Schedule of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 2,707.1
Other comprehensive income (loss) before reclassifications	51.4	$ 48.5
Amounts reclassified from accumulated other comprehensive income (loss)	3.4	4.4
Ending balance	3,014.7
Foreign currency adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(6.2)	(194.0)
Other comprehensive income (loss) before reclassifications	49.3	43.0
Amounts reclassified from accumulated other comprehensive income (loss)	0.0	0.0
Ending balance	43.1	(151.0)
Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	5.2	7.1
Other comprehensive income (loss) before reclassifications	1.5	1.1
Amounts reclassified from accumulated other comprehensive income (loss)	0.4	(0.5)
Ending balance	7.1	7.7
Pension and other postretirement benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(239.3)	(291.5)
Other comprehensive income (loss) before reclassifications	0.6	4.4
Amounts reclassified from accumulated other comprehensive income (loss)	3.0	4.9
Ending balance	(235.7)	(282.2)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(240.3)	(478.4)
Ending balance	$ (185.5)	$ (425.5)