Stock-Based Compensation - Summary of Stock Option Activity Under Plans (Details)	9 Months Ended
	Sep. 30, 2016 $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares Subject to Outstanding Options, Beginning Balance | shares	1,318,647
Shares Subject to Outstanding Options, granted | shares	786,034
Shares Subject to Outstanding Options, exercised | shares	(18,913)
Shares Subject to Outstanding Options, canceled | shares	(50,991)
Shares Subject to Outstanding Options, Ending Balance | shares	2,034,777
Weighted Average Exercise Price Per Share, Beginning Balance | $ / shares	$ 2.29
Weighted Average Exercise Price Per Share, granted | $ / shares	10.02
Weighted Average Exercise Price Per Share, exercised | $ / shares	0.71
Weighted Average Exercise Price Per Share, cancelled | $ / shares	5.19
Weighted Average Exercise Price Per Share, Ending Balance | $ / shares	$ 5.22