Cash Equivalents and Investments - Schedule of Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value (Details) - USD ($) $ in Thousands	Oct. 31, 2023	Jan. 31, 2023
Cash Equivalents, Fair Value
Less than 12 months, fair value	$ 4,997	$ 12,348
12 months or greater, fair value	0	0
Total, fair value	4,997	12,348
Cash Equivalents, Gross Unrealized Losses
Less than 12 months, accumulated losses	(1)	(2)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(1)	(2)
Investments, Fair Value
Less than 12 months, fair value	2,303,213	2,105,083
12 months or greater, fair value	705,369	969,202
Total, fair value	3,008,582	3,074,285
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(13,138)	(14,735)
12 months or greater, accumulated losses	(11,672)	(24,012)
Total, accumulated losses	(24,810)	(38,747)
Cash Equivalents And Debt Securities, Available-For-Sale [Abstract]
Less than 12 months, fair value	2,308,210	2,117,431
12 months or greater, fair value	705,369	969,202
Total, fair value	3,013,579	3,086,633
Cash Equivalents And Debt Securities, Available-For-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, accumulated losses	(13,139)	(14,737)
12 months or greater, accumulated losses	(11,672)	(24,012)
Total, accumulated losses	(24,811)	(38,749)
Corporate notes and bonds
Investments, Fair Value
Less than 12 months, fair value	873,774	899,655
12 months or greater, fair value	460,730	736,431
Total, fair value	1,334,504	1,636,086
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(7,142)	(8,521)
12 months or greater, accumulated losses	(5,805)	(14,949)
Total, accumulated losses	(12,947)	(23,470)
U.S. government and agency securities
Investments, Fair Value
Less than 12 months, fair value	785,354	387,207
12 months or greater, fair value	244,639	232,771
Total, fair value	1,029,993	619,978
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(5,392)	(3,157)
12 months or greater, accumulated losses	(5,867)	(9,063)
Total, accumulated losses	(11,259)	(12,220)
Commercial paper
Investments, Fair Value
Less than 12 months, fair value	490,963	561,793
12 months or greater, fair value	0	0
Total, fair value	490,963	561,793
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(439)	(1,947)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(439)	(1,947)
Certificates of deposit
Investments, Fair Value
Less than 12 months, fair value	153,122	256,428
12 months or greater, fair value	0	0
Total, fair value	153,122	256,428
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(165)	(1,110)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(165)	(1,110)
Commercial paper
Cash Equivalents, Fair Value
Less than 12 months, fair value	4,997	9,304
12 months or greater, fair value	0	0
Total, fair value	4,997	9,304
Cash Equivalents, Gross Unrealized Losses
Less than 12 months, accumulated losses	(1)	(1)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	$ (1)	(1)
Certificates of deposit
Cash Equivalents, Fair Value
Less than 12 months, fair value		3,044
12 months or greater, fair value		0
Total, fair value		3,044
Cash Equivalents, Gross Unrealized Losses
Less than 12 months, accumulated losses		(1)
12 months or greater, accumulated losses		0
Total, accumulated losses		$ (1)