Cash Equivalents and Investments - Schedule of Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value (Details) - USD ($) $ in Thousands	Jul. 31, 2023	Jan. 31, 2023
Cash Equivalents, Fair Value
Less than 12 months, fair value	$ 16,893	$ 12,348
12 months or greater, fair value	0	0
Total, fair value	16,893	12,348
Cash Equivalents, Gross Unrealized Losses
Less than 12 months, accumulated losses	(4)	(2)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(4)	(2)
Investments, Fair Value
Less than 12 months, fair value	2,846,482	2,105,083
12 months or greater, fair value	817,990	969,202
Total, fair value	3,664,472	3,074,285
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(14,740)	(14,735)
12 months or greater, accumulated losses	(16,084)	(24,012)
Total, accumulated losses	(30,824)	(38,747)
Cash Equivalents And Debt Securities, Available-For-Sale [Abstract]
Less than 12 months, fair value	2,863,375	2,117,431
12 months or greater, fair value	817,990	969,202
Total, fair value	3,681,365	3,086,633
Cash Equivalents And Debt Securities, Available-For-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, accumulated losses	(14,744)	(14,737)
12 months or greater, accumulated losses	(16,084)	(24,012)
Total, accumulated losses	(30,828)	(38,749)
Corporate notes and bonds
Investments, Fair Value
Less than 12 months, fair value	979,478	899,655
12 months or greater, fair value	564,056	736,431
Total, fair value	1,543,534	1,636,086
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(6,794)	(8,521)
12 months or greater, accumulated losses	(8,772)	(14,949)
Total, accumulated losses	(15,566)	(23,470)
U.S. government and agency securities
Investments, Fair Value
Less than 12 months, fair value	894,573	387,207
12 months or greater, fair value	253,934	232,771
Total, fair value	1,148,507	619,978
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(6,556)	(3,157)
12 months or greater, accumulated losses	(7,312)	(9,063)
Total, accumulated losses	(13,868)	(12,220)
Commercial paper
Investments, Fair Value
Less than 12 months, fair value	756,598	561,793
12 months or greater, fair value	0	0
Total, fair value	756,598	561,793
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(1,076)	(1,947)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(1,076)	(1,947)
Certificates of deposit
Investments, Fair Value
Less than 12 months, fair value	215,833	256,428
12 months or greater, fair value	0	0
Total, fair value	215,833	256,428
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(314)	(1,110)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(314)	(1,110)
Commercial paper
Cash Equivalents, Fair Value
Less than 12 months, fair value	10,901	9,304
12 months or greater, fair value	0	0
Total, fair value	10,901	9,304
Cash Equivalents, Gross Unrealized Losses
Less than 12 months, accumulated losses	(3)	(1)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(3)	(1)
U.S. government securities
Cash Equivalents, Fair Value
Less than 12 months, fair value	5,992
12 months or greater, fair value	0
Total, fair value	5,992
Cash Equivalents, Gross Unrealized Losses
Less than 12 months, accumulated losses	(1)
12 months or greater, accumulated losses	0
Total, accumulated losses	$ (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)