Stockholders' Equity - Summary of Activity Related to Stock Option Plans (Details) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares Available for Grant, Beginning Balance	16,845,316
Options Outstanding, Number of Shares, Beginning Balance	20,995,756
Shares Available for Grant, Granted	(835,669)
Options Outstanding, Number of Shares, Granted	835,669
Options Outstanding, Number of Shares, Exercised	(348,776)
Shares Available for Grant, Ending Balance	16,009,647
Options Outstanding, Number of Shares, Ending Balance	21,482,649
Options Outstanding, Number of Shares, Vested and exercisable	21,482,649
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 | $ / shares	$ 32.39
Options Outstanding, Weighted-Average Exercise Price, Granted | $ / shares	99.67
Options Outstanding, Weighted-Average Exercise Price, Exercised | $ / shares	10.02
Options Outstanding, Weighted-Average Exercise Price, Ending Balance | $ / shares	35.37
Options Outstanding, Weighted-Average Exercise Price, Vested and exercisable | $ / shares	$ 35.37
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted-Average Remaining Contractual Term, Ending Balance	6 years 2 months 23 days
Weighted-Average Remaining Contractual Term, Vested and exercisable	6 years 2 months 23 days
Aggregate Intrinsic Value, Ending Balance | $	$ 1,447,088
Aggregate Intrinsic Value, Vested and exercisable | $	$ 1,447,088