Liquidity - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	12 Months Ended
	Oct. 31, 2015	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Accumulated deficit			$ (117,466)	$ (78,138)
Cash, cash equivalents, and short-term investments			186,700
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs			74,430	$ 26,802
Net proceeds from IPO after underwriting discounts, commissions and estimated offering expenses	$ 81,800		$ 81,777
Series C and Series D Redeemable Convertible Preferred Stock
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Proceeds from issuance of redeemable convertible preferred stock, net of issuance costs		$ 73,200