Accumulated Other Comprehensive Income (Loss) - Details of Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			$ 609.7
Other comprehensive income (loss) before reclassifications			25.9	$ 3.0
Less: amounts reclassified from accumulated other comprehensive income (loss)			2.6	(26.5)
Other comprehensive (loss) income, net of taxes	$ (21.6)	$ 10.8	28.5	(23.5)
Ending balance	339.5		339.5
Unrecognized Pension Items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(276.7)	(266.0)
Other comprehensive income (loss) before reclassifications			1.8	0.2
Less: amounts reclassified from accumulated other comprehensive income (loss)			3.5	3.6
Other comprehensive (loss) income, net of taxes			5.3	3.8
Ending balance	(271.4)	(262.2)	(271.4)	(262.2)
Cumulative Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(701.9)	(564.0)
Other comprehensive income (loss) before reclassifications			73.8	30.5
Less: amounts reclassified from accumulated other comprehensive income (loss)			0.0	(46.0)
Other comprehensive (loss) income, net of taxes			73.8	(15.5)
Ending balance	(628.1)	(579.5)	(628.1)	(579.5)
Cumulative Translation Adjustment | Intra-entity transactions
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Cumulative translation adjustment (loss) after tax	23.3	23.3	23.3	23.3
Unrecognized Gains (Losses) on Derivative Instruments | Net Investment Hedge
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			21.0	1.7
Other comprehensive income (loss) before reclassifications			(44.4)	(7.1)
Less: amounts reclassified from accumulated other comprehensive income (loss)			0.0	0.0
Other comprehensive (loss) income, net of taxes			(44.4)	(7.1)
Ending balance	(23.4)	(5.4)	(23.4)	(5.4)
Unrecognized Gains (Losses) on Derivative Instruments | Cash Flow
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			8.5	8.3
Other comprehensive income (loss) before reclassifications			(5.3)	(20.6)
Less: amounts reclassified from accumulated other comprehensive income (loss)			(0.9)	15.9
Other comprehensive (loss) income, net of taxes			(6.2)	(4.7)
Ending balance	2.3	3.6	2.3	3.6
Accumulated Other Comprehensive Income (Loss), Net of Taxes
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance			(949.1)	(820.0)
Ending balance	$ (920.6)	$ (843.5)	$ (920.6)	$ (843.5)