Accumulated Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Apr. 01, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ (411.8)								$ (336.1)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of an accounting change							$ (3.7)	$ (0.7)		$ 12.2
Unrealized Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(341.9)	$ (289.7)	$ (286.6)	$ (292.6)	$ (276.2)	$ (166.6)			(299.4)	(208.8)	$ (208.8)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of an accounting change										0.0
Current year deferrals to AOCI	(52.2)	(5.7)	12.8	(16.4)	(109.6)	42.2
Reclassifications from AOCI to Net income (loss)	0.0	2.6	0.0	0.0	0.0	0.0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(52.2)	(3.1)	12.8	(16.4)	(109.6)	42.2
Pension Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(35.7)	(36.0)	(36.4)	(32.2)	(32.4)	(30.8)			(36.4)	(31.4)	(31.4)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of an accounting change										0.0
Current year deferrals to AOCI	0.0	(0.1)	0.0	0.0	(1.5)	0.0
Reclassifications from AOCI to Net income (loss)	0.3	0.5	0.0	0.2	(0.1)	0.6
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	0.3	0.4	0.0	0.2	(1.6)	0.6
Unrealized Gain (Loss) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss				0.0	0.0	0.0				0.0	0.8
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of an accounting change										(0.8)
Current year deferrals to AOCI				0.0	0.0	0.0
Reclassifications from AOCI to Net income (loss)				0.0	0.0	0.0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent				0.0	0.0	0.0
Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(34.2)	(30.3)	(12.7)	12.4	9.0	4.7			(0.3)	(1.6)	(1.6)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of an accounting change										0.0
Current year deferrals to AOCI	(4.4)	(17.3)	(11.4)	3.5	4.5	6.4
Reclassifications from AOCI to Net income (loss)	0.5	(0.3)	(1.0)	(0.1)	(0.2)	(0.1)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(3.9)	(17.6)	(12.4)	3.4	4.3	6.3
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(411.8)	(356.0)	(335.7)	(312.4)	(299.6)	(192.7)			$ (336.1)	(241.8)	$ (241.0)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Cumulative effect of an accounting change										$ (0.8)
Current year deferrals to AOCI	(56.6)	(23.1)	1.4	(12.9)	(106.6)	48.6
Reclassifications from AOCI to Net income (loss)	0.8	2.8	(1.0)	0.1	(0.3)	0.5
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ (55.8)	$ (20.3)	$ 0.4	$ (12.8)	$ (106.9)	$ 49.1