Income Taxes - Income Tax (Benefit) Expense Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
U.S. federal statutory tax rate	21.00%	35.00%	35.00%
Taxes computed at U.S. statutory rate	$ (11.2)	$ (91.1)	$ (81.1)
Impact of TCJA	(41.8)	(46.3)	0.0
Net change in reserve	(4.9)	(10.6)	(27.4)
State income taxes, net of federal benefit	(3.1)	1.7	(0.1)
Change in valuation allowances	27.5	43.3	53.1
Change of tax rate	8.3	(19.4)	11.8
Provision for tax on undistributed foreign earnings	7.0	1.5	11.4
Impact of transaction costs	0.0	0.0	(24.5)
Settlement of Series B Convertible Preferred Stock	0.0	0.0	(34.3)
Goodwill impairment	0.0	0.0	6.2
Other, net	(0.6)	9.0	9.8
Income tax expense (benefit)	$ 23.8	$ (68.6)	$ (41.3)
Effective tax rate	(44.70%)	26.30%	17.80%
Domestic
Income Taxes [Line Items]
Tax on foreign operations	$ 31.2	$ 35.0	$ 17.7
Foreign
Income Taxes [Line Items]
Tax on foreign operations	$ 11.4	$ 8.3	$ 16.1