Warrants - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended			12 Months Ended
	Aug. 22, 2016	Sep. 30, 2016	Aug. 31, 2015	Jul. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jul. 23, 2015
Convertible Preferred Stock Warrants [Line Items]
Change in the fair value of the warrant					$ 3	$ 45	$ 20
Convertible preferred stock warrant liability					93	$ 93
2016 Placement Warrants Liability					2,723
2016 Placement Warrants
Convertible Preferred Stock Warrants [Line Items]
Warrants issued		1,380,745
Exercise price		$ 0.125
Common stock warrants, expiry term		7 years
Private placement, common shares		4,602,506
Sales of share common stock, per share		$ 2.95
Private placement, value		$ 13,200
Gross proceeds from Issuance of Private Placement					$ 13,800
Fair value of warrants upon issuance under Private Placement	$ 2,700
Expected term (in years)	7 years				6 years 8 months 12 days
Expected volatility	61.60%				63.60%
Risk-free interest rate	1.40%				2.30%
Expected dividend yield	0.00%				0.00%
Gain related to change in fair value					$ 3
2016 Placement Warrants Liability					2,700
Common Stock Warrant
Convertible Preferred Stock Warrants [Line Items]
Estimated fair value of the warrants issued to placement agents					$ 316
Expected term (in years)					5 years
Expected volatility					31.80%
Risk-free interest rate					1.60%
Expected dividend yield					0.00%
Common Stock Warrant | Insiders
Convertible Preferred Stock Warrants [Line Items]
Warrants issued			198,760	198,760
Exercise price			$ 5.00	$ 5.00
Common stock warrants, expiry term			5 years	5 years
Term Loan | Series C Convertible Preferred Stock
Convertible Preferred Stock Warrants [Line Items]
Warrants issued					128,231			128,231