Net Income per Share - Numerators and Denominators of the Basic and Diluted EPS Computations for Common Stock (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Weighted average shares used in computing net income per share, basic (in shares)	153,251	150,666	147,796
Net income per share, basic (in usd per share)	$ 2.79	$ 2.52	$ 2.04
Reallocation as a result of conversion of Class B to Class A common stock:
Weighted average shares used in computing net income per share, diluted (in shares)	162,277	160,732	158,296
Net income per share, diluted (in usd per share)	$ 2.63	$ 2.36	$ 1.90
Class A common stock
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net income, basic	$ 386,180	$ 341,866	$ 266,104
Weighted average shares used in computing net income per share, basic (in shares)	138,474	135,547	130,610
Net income per share, basic (in usd per share)	$ 2.79	$ 2.52	$ 2.04
Net income, basic	$ 386,180	$ 341,866	$ 266,104
Reallocation as a result of conversion of Class B to Class A common stock:
Net income, basic	41,210	38,132	35,014
Reallocation of net income to Class B common stock	0	0	0
Net income, diluted	$ 427,390	$ 379,998	$ 301,118
Conversion of Class B to Class A common stock (in shares)	14,777	15,119	17,186
Effect of potentially dilutive common shares (in shares)	9,026	10,066	10,500
Weighted average shares used in computing net income per share, diluted (in shares)	162,277	160,732	158,296
Net income per share, diluted (in usd per share)	$ 2.63	$ 2.36	$ 1.90
Class B common stock
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net income, basic	$ 41,210	$ 38,132	$ 35,014
Weighted average shares used in computing net income per share, basic (in shares)	14,777	15,119	17,186
Net income per share, basic (in usd per share)	$ 2.79	$ 2.52	$ 2.04
Net income, basic	$ 41,210	$ 38,132	$ 35,014
Reallocation as a result of conversion of Class B to Class A common stock:
Net income, basic	0	0	0
Reallocation of net income to Class B common stock	21,480	21,409	17,652
Net income, diluted	$ 62,690	$ 59,541	$ 52,666
Conversion of Class B to Class A common stock (in shares)	0	0	0
Effect of potentially dilutive common shares (in shares)	9,026	10,066	10,500
Weighted average shares used in computing net income per share, diluted (in shares)	23,803	25,185	27,686
Net income per share, diluted (in usd per share)	$ 2.63	$ 2.36	$ 1.90