Stockholders' Equity - Summary Of Activity Related To Stock Option Plans (Details) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Available for Grant, Beginning Balance	3,406,317
Options Outstanding, Number of Shares, Beginning Balance	3,526,898
Options Outstanding, Number of Shares, Granted	391,239
Options Outstanding, Number of Shares, Exercised	(639,378)
Shares Available for Grant, Ending Balance	3,015,078
Options Outstanding, Number of Shares, Ending Balance	3,278,759
Options Outstanding, Number of Shares, Vested and exercisable	3,278,759
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options Outstanding, Weighted-Average Exercise Price, Beginning Balance	$ 95.25
Options Outstanding, Weighted-Average Exercise Price, Granted	$ 409.70
Options Outstanding, Weighted-Average Exercise Price, Exercised	$ 88.82
Options Outstanding, Weighted-Average Exercise Price, Ending Balance	$ 134.02
Options Outstanding, Weighted-Average Exercise Price, Vested and exercisable	$ 134.02
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-Average Remaining Contractual Term, Ending Balance	5 years 11 months 19 days
Weighted-Average Remaining Contractual Term, Vested and exercisable	5 years 11 months 19 days
Aggregate Intrinsic Value, Ending Balance	$ 1,041,797
Aggregate Intrinsic Value, Vested and exercisable	$ 1,041,797