Stockholders' Equity - Summary Of Activity Related To Stock Option Plans (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Available for Grant, Beginning Balance	2,860,744
Options Outstanding, Number of Shares, Beginning Balance	3,263,631
Shares Available for Grant, Granted	(148,156)
Options Outstanding, Number of Shares, Granted	148,156
Options Outstanding, Number of Shares, Exercised	(204,880)
Shares Available for Grant, Ending Balance	2,712,588
Options Outstanding, Number of Shares, Ending Balance	3,206,907
Options Outstanding, Number of Shares, Vested and exercisable	3,206,907
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	$ 151.53
Options Outstanding, Weighted-Average Exercise Price, Granted	$ 417.43
Options Outstanding, Weighted-Average Exercise Price, Exercised	$ 50.12
Options Outstanding, Weighted-Average Exercise Price, Ending Balance	$ 170.29
Options Outstanding, Weighted-Average Exercise Price, Vested and exercisable	$ 170.29
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-Average Remaining Contractual Term, Ending Balance	6 years 3 months 18 days
Weighted-Average Remaining Contractual Term, Vested and exercisable	6 years 3 months 18 days
Aggregate Intrinsic Value, Ending Balance	$ 801,626
Aggregate Intrinsic Value, Vested and exercisable	$ 801,626