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Marketable Securities - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended
Apr. 30, 2022
Apr. 30, 2021
Schedule of Available-for-sale Securities [Line Items]    
Sales and maturities of marketable securities $ 106,043 $ 73,848
Amortization of discounts and premiums, net 1,657 1,338
Other (Loss) Income, Net    
Schedule of Available-for-sale Securities [Line Items]    
Net realized gain (loss) $ (112) $ 0