Stock Incentive Plans - Summary of Stock Option Activity Under 2006 and 2016 Plans, Including Grants To Nonemployees (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Options Outstanding, Beginning balance	2,685,913	1,972,383	1,620,129
Options granted	361,385	915,080	429,474
Options exercised	(57,067)	(84,300)	(38,982)
Options forfeited	(13,013)	(117,250)	(38,238)
Options Outstanding, Ending balance	2,977,218	2,685,913	1,972,383	1,620,129
Options exercisable	1,940,798
Options vested and expected to vest	2,912,854
Options Outstanding, Weighted Average Exercise Price Per Share, Beginning Balance	$ 4.81	$ 3.70	$ 3.59
Options Outstanding, Weighted Average Exercise Price Per Share, Options granted	15.65	3.98	3.86
Options Outstanding, Weighted Average Exercise Price Per Share, Options exercised	2.33	3.71	1.30
Options Outstanding, Weighted Average Exercise Price Per Share, Options forfeited	6.92	3.94	3.34
Options Outstanding, Weighted Average Exercise Price Per Share, Ending Balance	6.16	$ 4.81	$ 3.70	$ 3.59
Options Outstanding, Weighted Average Exercise Price Per Share, Exercisable	4.35
Options Outstanding, Weighted Average Exercise Price Per Share, vested and expected to vest	$ 6.06
Options Outstanding, Weighted- Average Remaining Contractual Life (years)	6 years 11 months 5 days	7 years 7 months 17 days	7 years 10 months 10 days	8 years 2 months 12 days
Options exercisable, Weighted- Average Remaining Contractual Life (years)	6 years 3 months
Options vested and expected to vest, Weighted- Average Remaining Contractual Life (years)	7 years 22 days
Options Outstanding, Aggregate Intrinsic Value	$ 70,979	$ 11,589	$ 4,191
Options exercisable, Aggregate Intrinsic Value	49,775
Options vested and expected to vest, Aggregate Intrinsic Value	$ 69,746