Equity Award Plan Activities - Option and RSA Activity Rollforward (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Number of Shares Underlying Outstanding Options and RSAs (in thousands)
Options granted (in shares)	440
Options canceled (in shares)	(232)
Employee Stock Option and Restricted Stock
Number of Shares Underlying Outstanding Options and RSAs (in thousands)
Beginning balance, options (in shares)	11,630
Options granted (in shares)	440
Options exercised (in shares)	(825)
Options canceled (in shares)	(232)
Ending balance, options (in shares)	11,013	11,630
Vested and exercisable (in shares)	4,021
Vested and expected to vest (in shares)	10,449
Weighted- Average Exercise Price per Share
Outstanding beginning balance (usd per share)	$ 24.49
Options granted (usd per share)	56.88
Options exercised (usd per share)	7.71
Options canceled (usd per share)	29.16
Outstanding ending balance (usd per share)	26.94	$ 24.49
Vested and exercisable (usd per share)	13.25
Vested and expected to vest (usd per share)	$ 26.29
Weighted- Average Remaining Contractual Term and Aggregate Intrinsic Value of Stock Options Outstanding
Weighted-average remaining contractual term of stock options outstanding	7 years 4 months	7 years 7 months 6 days
Weighted-average remaining contractual term of stock options vested and exercisable	6 years 5 months
Weighted-average remaining contractual term of stock options vested and expected to vest	7 years 4 months
Aggregate intrinsic value of stock options outstanding	$ 420,519	$ 620,802
Aggregate intrinsic value of stock options outstanding vested and exercisable	207,297
Aggregate intrinsic value of stock options outstanding vested and expected to vest	$ 405,623