Income Taxes - Additional Information (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]
Effective income tax rate	24.20%	21.70%	25.70%	20.50%
Discrete income tax benefit	$ 1.0		$ 1.0
Discrete income tax expense			$ 3.2
Other tax expense (benefit)				$ (5.8)