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Composition of Certain Financial Statement Items - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jul. 31, 2021
Jul. 31, 2020
Jul. 31, 2021
Jul. 31, 2020
Composition Of Certain Financial Statement Items [Abstract]        
Depreciation expenses $ 2.9 $ 2.4 $ 5.6 $ 4.7