Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Income Taxes [Line Items]
Effective income tax rate	20.70%	12.90%	23.70%	17.80%
Discrete income tax expense			$ 2.9
Discrete income tax benefit		$ 3.2
Other tax expense (benefit)				$ (14.7)
Other Current Assets
Income Taxes [Line Items]
Income taxes receivable	$ 93.1		$ 93.1		$ 22.8