Income Taxes - Tables 3 & 4 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of Deferred Tax Assets [Abstract]
Net Operating Loss	$ 161.1	$ 301.3
Property, net	48.2	40.7
Insurance Reserve	26.0	25.6
Stock-based compensation	23.4	23.7
Allowance for doubtful accounts	24.5	18.0
Alternative minimum tax	10.6	10.5
Carrying value of partnerships	22.1	23.8
Other accruals	25.7	20.6
Tax credits	14.0	9.9
Noncontrolling interest	10.6	0.0
Other	0.8	1.6
Total deferred income tax assets	367.0	475.7
Less: Valuation allowance	(27.6)	(23.0)
Net deferred income tax assets	339.4	452.7
Components of Deferred Tax Liabilities [Abstract]
Intangibles	(112.8)	(97.5)
Convertible debt interest	(35.3)	(31.7)
Other	(0.5)	(5.7)
Total deferred income tax liabilities	(148.6)	(134.9)
Net deferred income tax assets	190.8	317.8
Less: Current deferred tax assets	0.0	188.4
Noncurrent deferred tax assets	190.8	129.4
Gross Unrecognized Income Tax Benefits
Gross unrecognized income tax benefits, Beginning Balance	0.9	1.1	$ 78.0
Gross amount of increases in unrecognized tax benefits related to prior periods	1.7	0.7	46.7
Gross amount of decreases in unrecognized tax benefits related to prior periods		(0.9)	(1.9)
Decreases in unrecognized tax benefits relating to settlements with taxing authorities			(121.7)
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	0.3
Gross unrecognized income tax benefits, Ending Balance	2.9	0.9	1.1
Unrecognized Tax Benefits, Accrued Interest and Penalties
Unrecognized Tax Benefits, Accrued interest and penalties, Beginning Balance	0.0	0.3	0.0
Gross amount of increases in unrecognized tax benefits related to prior periods	0.0	0.1	0.3
Gross amount of decreases in unrecognized tax benefits related to prior periods		(0.4)	0.0
Decreases in unrecognized tax benefits relating to settlements with taxing authorities			0.0
Unrecognized Tax Benefits, Accrued interest and penalties, Ending Balance	0.0	$ 0.0	$ 0.3
Gross amount of increases in unrecognized tax benefits related to current period	$ 0.0