Income Taxes Income Taxes - Rollforward of Deferred Tax Assets Valuation Allowance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance, Beginning Balance	$ 147.1	$ 135.3	$ 536.7
Deferred Tax Asset Valuation Allowance, Change in Assessment	(7.4)	2.5	(370.9)
Deferred Tax Asset Valuation Allowance, Current Year Operations	(4.0)	9.3	(30.5)
Deferred Tax Assets, Valuation Allowance, Ending Balance	135.7	147.1	135.3
Domestic Tax Authority [Member]
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance, Beginning Balance	0.0	0.0	352.8
Deferred Tax Asset Valuation Allowance, Change in Assessment	0.0	0.0	(339.6)
Deferred Tax Asset Valuation Allowance, Current Year Operations	0.0	0.0	(13.2)
Deferred Tax Assets, Valuation Allowance, Ending Balance	0.0	0.0	0.0
State and Local Jurisdiction [Member]
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance, Beginning Balance	45.0	44.7	122.4
Deferred Tax Asset Valuation Allowance, Change in Assessment	0.0	0.0	(35.0)
Deferred Tax Asset Valuation Allowance, Current Year Operations	(3.5)	0.3	(42.7)
Deferred Tax Assets, Valuation Allowance, Ending Balance	41.5	45.0	44.7
Foreign Tax Authority [Member]
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance, Beginning Balance	102.1	90.6	61.5
Deferred Tax Asset Valuation Allowance, Change in Assessment	(7.4)	2.5	3.7
Deferred Tax Asset Valuation Allowance, Current Year Operations	(0.5)	9.0	25.4
Deferred Tax Assets, Valuation Allowance, Ending Balance	$ 94.2	$ 102.1	$ 90.6