Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)	Jun. 30, 2018	Mar. 31, 2018
Assets:
Cash equivalents	$ 1,015,000	$ 1,011,000
Foreign currency forward contracts		9,000
Total assets measured at fair value on a recurring basis	1,015,000	1,020,000
Liabilities:
Foreign currency forward contracts	424,000
Total liabilities measured at fair value on a recurring basis	424,000	0
Level 1 [Member]
Assets:
Cash equivalents	1,015,000	1,011,000
Total assets measured at fair value on a recurring basis	1,015,000	1,011,000
Level 2 [Member]
Assets:
Foreign currency forward contracts		9,000
Total assets measured at fair value on a recurring basis		$ 9,000
Liabilities:
Foreign currency forward contracts	424,000
Total liabilities measured at fair value on a recurring basis	$ 424,000