Fair Value Measurements - Schedule of Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Roll Forward]
Beginning balance	$ 1,923
Ending balance	1,217	$ 1,923
Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Roll Forward]
Beginning balance	1,923	3,227
Mark to market adjustment	(706)	(1,304)
Ending balance	$ 1,217	$ 1,923