Commitments and Contingencies - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Recurring [Member] - USD ($) $ in Thousands		Jun. 30, 2019	Mar. 31, 2019
Assets:
Total assets measured at fair value		$ 95,084	$ 101,145
Liabilities:
Total liabilities measured at fair value		190	70
Foreign currency forward contracts [Member]
Liabilities:
Total liabilities measured at fair value	[1]	190	70
Pension plan assets [Member]
Assets:
Total assets measured at fair value	[2]	10,933	10,416
Short-term Investments [Member]
Assets:
Total assets measured at fair value	[3]	84,151	90,729
Level 1 [Member]
Assets:
Total assets measured at fair value		84,151	90,729
Level 1 [Member] | Short-term Investments [Member]
Assets:
Total assets measured at fair value	[3]	84,151	90,729
Level 2 [Member]
Assets:
Total assets measured at fair value		10,933	10,416
Liabilities:
Total liabilities measured at fair value		190	70
Level 2 [Member] | Foreign currency forward contracts [Member]
Liabilities:
Total liabilities measured at fair value	[1]	190	70
Level 2 [Member] | Pension plan assets [Member]
Assets:
Total assets measured at fair value	[2]	$ 10,933	$ 10,416

[1] The fair value of foreign currency forward contracts has been determined by calculating the present value of future cash flows, estimated using market-based observable inputs including forward and spot exchange rates and interest rate curves obtained from third party market price quotations.

[2] The fair value of pension plan assets has been determined as the surrender value of the portfolio of active insured employees held within the Swiss Life collective investment fund. See Note 10, “Defined Benefit Pension Plans”.

[3] The fair value of short-term investments has been determined based on the quoted value of the units held in the money market fund at the balance sheet date. See Note 2, “Summary of Significant Accounting Policies – Short-term Investments”.