Stock-based Compensation Stock-based Compensation (Details 4) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Stock Option Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per share	$ 0.00	$ 7.65	$ 7.32	$ 5.92
Total fair value awards granted	$ 0	$ 278	$ 4,446	$ 6,095
Total fair value of awards vested	0	33	4,662	5,059
Total intrinsic value of options exercised	4,884	1,910	26,217	3,748
Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per share	$ 0.00	$ 31.30	$ 32.85	$ 23.91
Total fair value of awards granted	0	2,427	21,830	28,063
Total fair value of awards vested	287	222	28,049	13,541
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per share	$ 0.00	$ 0.00	$ 7.87	$ 5.25
Total fair value of shares expected to be issued	$ 0	$ 0	$ 591	$ 552