Accumulated Other Comprehensive Income (Loss) ("AOCI") Table 1 (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
As of December 31, 2018	$ (1,150.0)
As of March 31, 2019	(1,182.7)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
As of December 31, 2018	(744.7)
Foreign currency translation adjustments	4.6
Unrealized gain (loss) on derivative instruments	0.0
Reclassification of derivative (gain) loss to income	0.0
Amortization of net prior service (benefit) cost and net actuarial (gain) loss to income	0.0
Ownership share of unconsolidated subsidiaries' other comprehensive income (loss)	0.0
Tax benefit (expense)	12.1
Net current-period other comprehensive income (loss)	16.7
Reclassification of stranded tax effects	(61.0)
As of March 31, 2019	(789.0)
Gain (loss) on derivative and non-derivative instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
As of December 31, 2018	(17.8)
Foreign currency translation adjustments	72.8
Unrealized gain (loss) on derivative instruments	(39.4)
Reclassification of derivative (gain) loss to income	0.1
Amortization of net prior service (benefit) cost and net actuarial (gain) loss to income	0.0
Ownership share of unconsolidated subsidiaries' other comprehensive income (loss)	0.0
Tax benefit (expense)	(8.5)
Net current-period other comprehensive income (loss)	25.0
Reclassification of stranded tax effects	(16.1)
As of March 31, 2019	(8.9)
Pension and postretirement benefit adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
As of December 31, 2018	(327.2)
Foreign currency translation adjustments	0.0
Unrealized gain (loss) on derivative instruments	0.0
Reclassification of derivative (gain) loss to income	0.0
Amortization of net prior service (benefit) cost and net actuarial (gain) loss to income	(0.9)
Ownership share of unconsolidated subsidiaries' other comprehensive income (loss)	0.0
Tax benefit (expense)	0.3
Net current-period other comprehensive income (loss)	(0.6)
Reclassification of stranded tax effects	2.3
As of March 31, 2019	(325.5)
Equity method investments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
As of December 31, 2018	(60.3)
Foreign currency translation adjustments	0.0
Unrealized gain (loss) on derivative instruments	0.0
Reclassification of derivative (gain) loss to income	0.0
Amortization of net prior service (benefit) cost and net actuarial (gain) loss to income	0.0
Ownership share of unconsolidated subsidiaries' other comprehensive income (loss)	1.4
Tax benefit (expense)	(0.4)
Net current-period other comprehensive income (loss)	1.0
Reclassification of stranded tax effects	0.0
As of March 31, 2019	(59.3)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
As of December 31, 2018	(1,150.0)
Foreign currency translation adjustments	77.4
Unrealized gain (loss) on derivative instruments	(39.4)
Reclassification of derivative (gain) loss to income	0.1
Amortization of net prior service (benefit) cost and net actuarial (gain) loss to income	(0.9)
Ownership share of unconsolidated subsidiaries' other comprehensive income (loss)	1.4
Tax benefit (expense)	3.5
Net current-period other comprehensive income (loss)	42.1
Reclassification of stranded tax effects	(74.8)
As of March 31, 2019	$ (1,182.7)