The Company and Basis of Presentation - Additional Information (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Apr. 12, 2016 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) Segment $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of operating segments | Segment		1
Convertible preferred stock, terms of conversion		The convertible preferred stock was automatically convertible into shares of common stock at the then-current conversion rate upon (i) a vote of 62% of the outstanding Series B convertible preferred stock, or (ii) the closing of a firm commitment underwritten public offering that met aggregate gross proceed and pricing terms.
Capital stock, shares authorized	510,000,000
Common stock, shares authorized	500,000,000	500,000,000	25,000,000
Preferred stock, shares authorized	10,000,000	10,000,000	10,000,000
Common stock, par value | $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, par value | $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, shares outstanding		0	0
Stock split ratio		0.095
Working capital | $		$ 62,500
Accumulated deficit | $		(45,277)	$ (23,579)
Cash, cash equivalents and marketable securities | $		$ 63,500
Common Stock
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of shares issued		5,482,000
Proceeds from issuance of common stock upon initial public offering, net | $	$ 47,300
Convertible preferred stock converted into common stock	7,172,496	0
IPO
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Convertible preferred stock, terms of conversion		Ratio of one share of common stock for each share of convertible preferred stock
Convertible preferred stock converted into common stock	7,172,496
Convertible preferred stock reclassified into common stock and additional paid-in-capital | $	$ 58,300
IPO | Common Stock
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of shares issued	5,481,940
Public offering price | $ / shares	$ 10.00
Underwriting discounts and commissions | $	$ 3,800
Offering costs | $	$ 3,700
Underwriters' Over-allotment Option | Common Stock
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Number of shares issued	481,940