Equity Award Plans - Summary of Activity of Restricted Common Stock, RSAs and RSUs and Information Related to Unvested Restricted Stock, RSAs and RSUs and those Expected to Vest (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Options expected to vest (usd per share)	$ 10.60
Restricted stock awards and restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Beginning balance, shares outstanding (in shares)	8,341	3,602	3,009
Granted (in shares)	16,876	6,734	1,949
Vested (in shares)	(2,783)	(1,482)	(2,115)
Canceled/forfeited (shares)	(2,380)	(809)	(262)
Granted in connection with acquisitions (in shares)		296	1,021
Ending balance, shares outstanding (in shares)	20,054	8,341	3,602
Beginning balance, weighted average grant date fair value (usd per share)	$ 39.57	$ 27.20	$ 2.20
Granted, weighted average grant date fair value (usd per share)	32.25	42.12	31.59
Vested, weighted average grant date fair value (usd per share)	35.66	16.04	3.26
Forfeited, weighted average grant date fair value (usd per share)	41.11	40.93	6.73
Ending balance, weighted average grant date fair value (usd per share)	$ 33.68	39.57	27.20
Expected to vest (in shares)	18,822
Options expected to vest (usd per share)	$ 33.78
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Granted in connection with acquisitions, weighted-average grant-date fair value (usd per share)		$ 26.44	$ 37.65
Unvested, weighted-average remaining contractual term	1 year 7 months 6 days
Expected to vest, weighted-average remaining contractual term	1 year 7 months 6 days
Unvested, aggregate intrinsic value	$ 415,912
Expected to vest, aggregate intrinsic value	$ 390,359