Accumulated Other Comprehensive Income (Loss) - Changes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity	$ 8,829.9	$ 1,790.5	$ 8,829.9	$ 1,790.5		$ 1,869.9
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			1,869.9
Other comprehensive income (loss) before reclassifications			93.0	(57.9)
Amounts reclassified from accumulated other comprehensive income (loss)			15.6	10.6
Total other comprehensive income (loss), net of tax	145.8	(43.6)	108.6	$ (47.3)
Balance at end of period	8,771.7		$ 8,771.7
Accounting Standards Update [Extensible List]			us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201802Member
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity	(147.4)	(302.5)	$ (147.4)	$ (302.5)	$ (293.2)	$ (256.0)	$ (258.9)	$ (247.0)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(256.0)	(247.0)
Balance at end of period	(147.4)	(302.5)	(147.4)	(302.5)
Accumulated Other Comprehensive Income (Loss) | Cumulative Effect, Period of Adoption, Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity								$ (8.2)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period				(8.2)
Foreign Currency Translation Adjustments, Net
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(193.6)	(190.6)
Other comprehensive income (loss) before reclassifications			95.3	(55.3)
Amounts reclassified from accumulated other comprehensive income (loss)			0.0	0.0
Total other comprehensive income (loss), net of tax			95.3	(55.3)
Balance at end of period	(98.3)	(247.4)	(98.3)	(247.4)
Foreign Currency Translation Adjustments, Net | Cumulative Effect, Period of Adoption, Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period				(1.5)
Unrecognized Gains (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(10.9)	(11.4)
Other comprehensive income (loss) before reclassifications			(3.0)	(4.6)
Amounts reclassified from accumulated other comprehensive income (loss)			13.9	9.3
Total other comprehensive income (loss), net of tax			10.9	4.7
Balance at end of period	0.0	(13.4)	0.0	(13.4)
Unrecognized Gains (Losses) on Cash Flow Hedges | Cumulative Effect, Period of Adoption, Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period				(6.7)
Pension and Other Postretirement Benefit Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(51.5)	(45.0)
Other comprehensive income (loss) before reclassifications			0.7	2.0
Amounts reclassified from accumulated other comprehensive income (loss)			1.7	1.3
Total other comprehensive income (loss), net of tax			2.4	3.3
Balance at end of period	$ (49.1)	$ (41.7)	$ (49.1)	(41.7)
Pension and Other Postretirement Benefit Plans | Cumulative Effect, Period of Adoption, Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period				$ 0.0