Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 20.7		$ 21.2	$ 60.6	$ 66.9
Effective tax rate (as a percent)	28.20%		27.70%	25.00%	30.10%
Effective tax rate excluding discrete benefits (as a percent)				30.60%
Benefit from favorable tax return to provision adjustments and release of reserves for uncertain tax positions	$ 1.8	$ 11.6	$ 1.7