Stockholders' Equity - Warrants - Additional Information (Detail) - USD ($)		1 Months Ended		12 Months Ended			36 Months Ended
	Dec. 31, 2014	Nov. 30, 2014	Sep. 30, 2014	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2016	Dec. 31, 2014
Class Of Stock [Line Items]
Warrants to purchase common stock	650,000	145,000	50,000	0			650,000
Warrants maturity term		5 years	5 years
Warrants earned, service period		17 months
Number of warrant shares vested upon satisfaction of specific performance metrics					95,000
Volatility		73.40%		72.99%	76.86%
Risk-free interest rate		1.21%		2.75%	1.81%
Weighted-average remaining contractual term of options exercisable				6 years 10 months 24 days
Consultation Service Agreement September 2014
Class Of Stock [Line Items]
Recognized expenses of warrants	$ 237,000
Consultation Service Agreement November 2014
Class Of Stock [Line Items]
Recognized expenses of warrants						$ 6,000
Minimum [Member]
Class Of Stock [Line Items]
Warrants exercisable price, per share				$ 6.84
Warrants maturity term							2 years
Maximum [Member]
Class Of Stock [Line Items]
Warrants exercisable price, per share				$ 7.62
Warrants maturity term							5 years
Warrants [Member]
Class Of Stock [Line Items]
Warrants exercisable price, per share		$ 6.84	$ 7.62
Estimated fair value of warrants		$ 74,000
Weighted-average remaining contractual term of options exercisable				6 months 10 days
Warrants [Member] | Consultants [Member]
Class Of Stock [Line Items]
Number of warrants exercised				0	0
Warrants [Member] | Minimum [Member]
Class Of Stock [Line Items]
Warrants exercisable price, per share	$ 1.70						$ 1.70
Warrants [Member] | Maximum [Member]
Class Of Stock [Line Items]
Warrants exercisable price, per share	$ 3.24						$ 3.24