Income Taxes - Textual (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Valuation Allowance [Line Items]
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions		$ 0.3
Noncontrolling interest		10.6	$ 0.0
Income Tax Effects Allocated Directly to Equity		(11.7)	(1.8)	$ 2.9
Income Taxes (Textual) [Abstract]
Increase Net Operating Loss Carryforward, Gross	$ 283.0
Net Operating Loss Carryforwards		161.1	301.3
Gross Operating Loss Carryforwards		261.6
Excess Tax Benefit from Share-based Compensation		14.6
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		4.6	(7.7)	(9.1)
Valuation Allowance		27.6	23.0
Gross Unrecognized Tax Benefits		2.9	0.9	1.1	$ 78.0
Unrecognized Tax Benefits, Accrued Interest		0.0	0.0	0.3	0.0
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		2.9	$ 0.9	$ 0.4	$ 76.0
Federal [Member]
Income Taxes (Textual) [Abstract]
Income Tax Benefit Resulting From Tax Settlement	$ 115.0
Net Operating Loss Carryforwards		91.6
Tax Credit Carryforward, Amount		14.0
State [Member]
Income Taxes (Textual) [Abstract]
Net Operating Loss Carryforwards		69.5
Minimum [Member]
Valuation Allowance [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit		0.5
Maximum [Member]
Valuation Allowance [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit		$ 2.9