Net Income (Loss) Per Ordinary Share - Computation of Basic and Diluted Net Income (Loss) Per Ordinary Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Oct. 31, 2021	Jul. 31, 2021	Apr. 30, 2021	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Oct. 31, 2021	Oct. 31, 2020
Numerator:
Net income (loss)	$ 756	$ (7,156)	$ (10,818)	$ (17,078)	$ (14,756)	$ (15,463)	$ (17,218)	$ (47,297)
Denominator:
Weighted-average ordinary shares - basic	36,792,187			34,819,880			36,391,676	34,460,172
Weighted-average ordinary shares - diluted	39,046,274			34,819,880			36,391,676	34,460,172
Net income (loss) per ordinary share:
Basic	$ 0.02			$ (0.49)			$ (0.47)	$ (1.37)
Diluted	$ 0.02			$ (0.49)			$ (0.47)	$ (1.37)
Stock options [Member]
Effect of potentially dilutive securities:
Effect of potentially dilutive securities	327,417
Restricted stock units [Member]
Effect of potentially dilutive securities:
Effect of potentially dilutive securities	1,921,723
Employee stock purchase plan awards [Member]
Effect of potentially dilutive securities:
Effect of potentially dilutive securities	4,947