Commitments and Contingencies - Additional Information (Detail) - USD ($)	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Rent Expense	$ 261,000	$ 264,000
Letters of credit issued percentage of cash collateralized basis	100.00%
Outstanding letters of credit	$ 0	0
Capital expenditure	0
Other commitment	0
Defined contribution 401(k) retirement plan, employer contribution	$ 32,000	$ 42,000