Employee Benefits and Stock-based Compensation - Stock Option Activities (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares, Outstanding	719,143	1,124,646	1,459,064
Shares, Granted	14,700	51,200	66,850
Shares, Assumed	163,581
Shares, Exercised	(269,287)	(421,736)	(366,886)
Shares, Forfeited	(7,669)	(11,618)	(14,931)
Shares, Expired	(1,146)	(23,349)	(19,451)
Shares, Outstanding	619,322	719,143	1,124,646
Shares, Exercisable	399,764
Weighted-Average Exercise Price, Outstanding	$ 38.33	$ 32.93	$ 28.31
Weighted-Average Exercise Price, Granted	110.19	59.54	50.56
Weighted-Average Exercise Price, Assumed	23.10
Weighted-Average Exercise Price, Exercised	28.23	24.52	15.52
Weighted-Average Exercise Price, Forfeited	68.95	46.69	46.29
Weighted-Average Exercise Price, Expired	9.86	70.11	64.53
Weighted-Average Exercise Price, Outstanding	40.08	38.33	32.93
Weighted-Average Exercise Price, Exercisable	42.40
Weighted-Average Grant-date Fair Value, Granted	50.28	$ 28.37	$ 25.35
Weighted-Average Acquisition-date Fair Value, Assumed	$ 173.04
Total Intrinsic Value of options Exercised	$ 25,622	$ 19,401	$ 13,263
Weighted-Average Remaining Contractual Term, Outstanding	5 years 3 months
Weighted-Average Remaining Contractual Term, Exercisable	3 years 11 months 1 day
Aggregate Intrinsic Value, Outstanding	$ 61,975
Aggregate Intrinsic Value, Exercisable	$ 39,076