Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
Mar. 31, 2021 USD ($) PerformanceObligation Customer	Mar. 31, 2020 USD ($) Customer	Mar. 31, 2019 Customer
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Maturities of short term investment interest-bearing securities	90 days
Accounts receivable due period	30 days
Revenue recognition, number of performance obligation \| PerformanceObligation	1
Unbilled account receivables	$ 17,213,000	$ 19,692,000
Capitalized software development costs	27,902,000	27,859,000
Accumulated amortization of software development costs	120,832,000	109,749,000
Impairment of goodwill, intangible assets or other long-lived assets	0
Goodwill	36,814,000	36,814,000
Accumulated amortization of goodwill	$ 2,069,000	$ 2,069,000
Computer Software Property and Equipment [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Amortization period of computer software	5 years
Customer Concentration Risk [Member] \| Sales Revenue, Net [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Maximum customer risk percentage	10.00%	10.00%	10.00%
Number of customer \| Customer	0	0	0
Credit Concentration Risk [Member] \| Accounts Receivable [Member]
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items]
Maximum customer risk percentage	10.00%	10.00%
Number of customer \| Customer	1	0

Accounts receivable are generally due within 30 days.

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For each balance sheet presented, the amount of accumulated amortization for capitalized computer software costs.

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