Income Taxes (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income tax provision (benefit)	$ 22,886,000	$ 13,276,000	$ 53,307,000	$ 32,071,000
Effective tax rate (as a percent)	39.00%	35.80%	39.90%	37.20%
Unrecognized tax benefits, including related interest and penalties			5,500,000
Unrecognized tax benefits that would impact the effective tax rate	4,900,000		4,900,000
Unrecognized tax benefits interest that would impact the effective tax rate	$ 600,000		$ 600,000