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, 2023	Jan. 31, 2022	Jan. 31, 2021
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Weighted average shares used in computing net income per share, basic (in shares)	155,385	153,251	150,666
Net income per share, basic (in usd per share)	$ 3.14	$ 2.79	$ 2.52
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)	162,437	162,277	160,732
Net income per share, diluted (in usd per share)	$ 3.00	$ 2.63	$ 2.36
Class A
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net income, basic	$ 441,425	$ 386,180	$ 341,866
Weighted average shares used in computing net income per share, basic (in shares)	140,640	138,474	135,547
Net income per share, basic (in usd per share)	$ 3.14	$ 2.79	$ 2.52
Net income, basic	$ 441,425	$ 386,180	$ 341,866
Reallocation as a result of conversion of Class B to Class A common stock:
Net income, basic	46,281	41,210	38,132
Reallocation of net income to Class B common stock	0	0	0
Net income, diluted	$ 487,706	$ 427,390	$ 379,998
Conversion of Class B to Class A common stock (in shares)	14,745	14,777	15,119
Effect of potentially dilutive common shares (in shares)	7,052	9,026	10,066
Weighted average shares used in computing net income per share, diluted (in shares)	162,437	162,277	160,732
Net income per share, diluted (in usd per share)	$ 3.00	$ 2.63	$ 2.36
Class B
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net income, basic	$ 46,281	$ 41,210	$ 38,132
Weighted average shares used in computing net income per share, basic (in shares)	14,745	14,777	15,119
Net income per share, basic (in usd per share)	$ 3.14	$ 2.79	$ 2.52
Net income, basic	$ 46,281	$ 41,210	$ 38,132
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	19,163	21,480	21,409
Net income, diluted	$ 65,444	$ 62,690	$ 59,541
Conversion of Class B to Class A common stock (in shares)	0	0	0
Effect of potentially dilutive common shares (in shares)	7,052	9,026	10,066
Weighted average shares used in computing net income per share, diluted (in shares)	21,797	23,803	25,185
Net income per share, diluted (in usd per share)	$ 3.00	$ 2.63	$ 2.36