Accumulated Other Comprehensive (Loss) - Schedule of Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	$ 2,036.6	$ 2,056.9	$ 2,058.0	$ 2,018.5
Other Comprehensive Income (Loss) before Reclassifications			27.9
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)			122.2
Total Other Comprehensive Income (Loss), Net of Tax			150.1
Net Current-period Other Comprehensive Loss (Income) Attributable to Noncontrolling Interest	35.9	(17.1)	150.1	(19.2)
Ending balance	1,833.9	2,034.6	1,833.9	2,034.6
Accumulated Other Comprehensive (Loss) Income
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(285.6)	(379.3)	(365.8)	(377.9)
Ending balance	(255.5)	$ (392.8)	(255.5)	$ (392.8)
Derivatives Instruments
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance			(16.6)
Ending balance	(9.8)		(9.8)
Pension and Postretirement Benefit Plans
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance			(238.5)
Ending balance	(124.1)		(124.1)
Currency Translation Adjustments
Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance			(110.7)
Ending balance	$ (121.6)		(121.6)
Derivatives Instruments
Accumulated Other Comprehensive Loss [Roll Forward]
Other Comprehensive Income (Loss) before Reclassifications			10.3
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)			(2.1)
Total Other Comprehensive Income (Loss), Net of Tax			8.2
Pension and Postretirement Benefit Plans
Accumulated Other Comprehensive Loss [Roll Forward]
Other Comprehensive Income (Loss) before Reclassifications			32.1
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)			124.3
Total Other Comprehensive Income (Loss), Net of Tax			156.4
Currency Translation Adjustments
Accumulated Other Comprehensive Loss [Roll Forward]
Other Comprehensive Income (Loss) before Reclassifications			(14.5)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)			0.0
Total Other Comprehensive Income (Loss), Net of Tax			(14.5)
Derivatives Instruments
Accumulated Other Comprehensive Loss [Roll Forward]
Net Current-period Other Comprehensive Loss (Income) Attributable to Noncontrolling Interest			(1.4)
Pension and Postretirement Benefit Plans
Accumulated Other Comprehensive Loss [Roll Forward]
Net Current-period Other Comprehensive Loss (Income) Attributable to Noncontrolling Interest			(42.0)
Currency Translation Adjustments
Accumulated Other Comprehensive Loss [Roll Forward]
Net Current-period Other Comprehensive Loss (Income) Attributable to Noncontrolling Interest			3.6
Total
Accumulated Other Comprehensive Loss [Roll Forward]
Net Current-period Other Comprehensive Loss (Income) Attributable to Noncontrolling Interest			$ (39.8)