Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2015	Jun. 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	$ 3.2	$ 3.2		$ 3.4
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	0.4	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		$ 40.0	$ 30.5