Income Taxes Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Income tax provision	$ 65.4	$ 61.8	$ 127.1	$ 117.3
Effective income tax rate, percent	31.40%	34.80%	32.80%	34.80%
Effective income tax rate, at federal statutory income tax rate, percent			35.00%
Cash paid for taxes, net of refunds received			$ 105.7	$ 83.3