Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Provisional income tax benefit			$ (46.3)
Measurement period adjustment, income tax expense (benefit)		$ 55.5
Measurement period adjustment, transition tax expense	$ 13.7
Discontinued operations, deferred tax asset	173.0	173.0	296.0
Discontinued operations, deferred tax asset, valuation allowance	75.0	75.0	206.0
Discontinued operations, deferred tax liability	450.0	450.0	487.0
Undistributed foreign earnings	29.5	29.5	21.9
Undistributed earnings of foreign subsidiaries	490.0	490.0
Valuation allowance	475.2	475.2	391.7
Increase (decrease) in valuation allowance		83.5
State operating loss carry forward	230.0	230.0
State tax credits	770.0	770.0
Foreign operating loss carry forward	562.0	562.0
Valuation allowance on foreign tax credit carryovers	32.9	32.9
State tax credits (net of federal tax)	5.8	$ 5.8
Tax carry-forward period		10 years
Unrecognized tax benefits	81.4	$ 81.4	90.3	$ 128.3	$ 112.2
Unrecognized tax benefits that would impact effective tax rate	80.6	80.6
Total unrecognized benefits expected to revers within the next twelve months	10.9	10.9
Interest and penalties related to unrecognized tax benefits		0.4	1.2	$ 5.5
Accrued interest and penalties related to unrecognized tax benefits	$ 12.9	$ 12.9	$ 13.0