Available-for-Sale Securities - Additional Information (Detail) |
3 Months Ended | 12 Months Ended |
---|---|---|
Mar. 31, 2020 |
Dec. 31, 2019 |
|
Investments Debt And Equity Securities [Abstract] | ||
Available-for-sale securities weighted average maturity period | 2 months 12 days | 2 months 12 days |