Investments - Additional Information (Detail) |
6 Months Ended |
---|---|
Sep. 30, 2019 | |
Minimum [Member] | |
Schedule of Held-to-maturity Securities [Line Items] | |
Treasury with original maturities period | 3 months |
Maximum [Member] | |
Schedule of Held-to-maturity Securities [Line Items] | |
Investment maturity date range end | Dec. 30, 2019 |
Treasury with original maturities period | 1 year |