Income Taxes - Income Taxes Additional Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Tax Disclosure [Abstract]
Effective income tax rate	12.90%	22.70%	17.80%	22.70%
Other tax benefit	$ 2.1		$ 2.1