Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Jun. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unrecognized Tax Benefit that Would Not Impact Effective Tax Rate, Tax Position with Uncertain Timing of Deductibility		$ 3.3		$ 3.4
Unrecognized Tax Benefits, Interest on Income Taxes Accrued		0.4		$ 3.8
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	$ 3.6
Income Tax Benefit Recognized from a Reduction in Liability for Unrecognized Tax Benefits	$ 2.3
Income Taxes Paid		$ 40.1	$ 30.1