Equity Incentive Plans - Summary of Stock Option Activity (Details) - Stock Option $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) $ / shares shares
Options Outstanding
Outstanding at beginning of period | shares	11,203,000
Options granted | shares	291,000
Options exercised | shares	(1,877,000)
Options forfeited or canceled | shares	(684,000)
Outstanding at end of period | shares	8,933,000
Vested and expected to vest at end of period | shares	8,826,000
Exercisable at end of period | shares	6,051,000
Weighted Average Exercise Price per Share
Outstanding at beginning of period | $ / shares	$ 9.49
Options granted | $ / shares	14.08
Options exercised | $ / shares	4.79
Options forfeited or canceled | $ / shares	13.85
Outstanding at end of period | $ / shares	10.29
Vested and expected to vest at end of period | $ / shares	10.24
Exercisable at end of period | $ / shares	$ 8.47
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding	6 years 6 months 18 days
Vested and expected to vest at end of period	6 years 6 months
Exercisable at end of period	5 years 7 months 28 days
Total Intrinsic Value | $	$ 73,081
Vested and expected to vest at end of period | $	72,672
Exercisable at end of period | $	$ 60,489