Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Tax Disclosure [Abstract]
Income tax provision	$ 61.4	$ 59.2	$ 108.5	$ 109.4
Effective income tax rate, percent	(35.00%)	(37.30%)	34.60%	36.60%
Effective income tax rate, at federal statutory income tax rate, percent	35.00%	35.00%	35.00%	35.00%
Cash paid for taxes, net of refunds received			$ 87.8	$ 58.1