Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S. tax reform - rate impact on deferred tax balance	$ 45.1	$ 0.0	$ 0.0
U.S. tax reform - deemed repatriation tax	36.6	0.0	0.0
Statutory tax (benefit) expense	(61.5)	(83.4)	16.0
Brazil non-taxable incentive	(3.9)	(5.8)	(4.2)
Valuation allowance	10.5	14.9	(0.7)
Foreign tax rate differential	(31.5)	(10.0)	(19.4)
Foreign subsidiary earnings	14.4	13.7	(9.1)
Accrual adjustments	4.1	1.1	1.5
Business tax credits	(0.6)	(0.7)	(1.4)
Non-deductible (non-taxable) items	17.9	2.3	4.2
Other	(1.3)	0.3	(0.6)
Income tax (benefit) expense	$ 29.8	$ (67.6)	$ (13.7)