Employee Benefits and Stock-based Compensation - Restricted Stock Unit Activities (Detail) - Restricted Stock Units [Member] - $ / shares	12 Months Ended
	Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares, Unvested, beginning balance	2,651,135	2,871,801	2,617,266
Shares, Granted	1,549,174	1,213,257	1,499,203
Shares, Vested	(1,513,972)	(1,367,309)	(1,162,883)
Shares, Forfeited	(112,978)	(66,614)	(81,785)
Shares, Unvested, ending balance	2,573,359	2,651,135	2,871,801
Weighted-Average Grant-Date Fair Value, Unvested, beginning balance	$ 85.41	$ 51.73	$ 50.30
Weighted-Average Grant-Date Fair Value, Granted	74.45	128.80	53.45
Weighted-Average Grant-Date Fair Value, Vested	71.32	53.85	50.53
Weighted-Average Grant-Date Fair Value, Forfeited	99.46	71.59	54.48
Weighted-Average Grant-Date Fair Value, Unvested, ending balance	$ 86.81	$ 85.41	$ 51.73