Warrants - Summary of Assumptions to Use Option Pricing Model (Detail)		1 Months Ended	3 Months Ended
	Aug. 22, 2016	Jan. 31, 2017	Mar. 31, 2017
2016 Placement Warrant
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Expected term (in years)	7 years		6 years 4 months 24 days
Expected volatility	61.60%		67.90%
Risk-free interest rate	1.40%		2.20%
Expected dividend yield	0.00%		0.00%
2017 Placement Warrant
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Expected term (in years)		7 years	6 years 9 months 18 days
Expected volatility		62.90%	67.90%
Risk-free interest rate		2.20%	2.20%
Expected dividend yield		0.00%	0.00%