Cash Equivalents and Investments - Schedule of Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value (Details) - USD ($) $ in Thousands	Oct. 31, 2024	Jan. 31, 2024
Cash Equivalents, Fair Value
Less than 12 months, fair value	$ 72,412	$ 338,893
12 months or greater, fair value	0	0
Total, fair value	72,412	338,893
Cash Equivalents, Gross Unrealized Losses
Less than 12 months, accumulated losses	(2)	(2)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(2)	(2)
Investments, Fair Value
Less than 12 months, fair value	1,125,769	1,395,409
12 months or greater, fair value	241,329	513,815
Total, fair value	1,367,098	1,909,224
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(2,863)	(2,728)
12 months or greater, accumulated losses	(462)	(5,465)
Total, accumulated losses	(3,325)	(8,193)
Cash Equivalents And Debt Securities, Available-For-Sale [Abstract]
Less than 12 months, fair value	1,198,181	1,734,302
12 months or greater, fair value	241,329	513,815
Total, fair value	1,439,510	2,248,117
Cash Equivalents And Debt Securities, Available-For-Sale, Unrealized Loss Position, Accumulated Loss [Abstract]
Less than 12 months, accumulated losses	(2,865)	(2,730)
12 months or greater, accumulated losses	(462)	(5,465)
Total, accumulated losses	(3,327)	(8,195)
Corporate notes and bonds
Investments, Fair Value
Less than 12 months, fair value	802,043	625,766
12 months or greater, fair value	69,203	321,952
Total, fair value	871,246	947,718
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(2,119)	(1,259)
12 months or greater, accumulated losses	(63)	(2,135)
Total, accumulated losses	(2,182)	(3,394)
U.S. government and agency securities
Investments, Fair Value
Less than 12 months, fair value	190,643	525,408
12 months or greater, fair value	172,126	191,863
Total, fair value	362,769	717,271
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(622)	(1,323)
12 months or greater, accumulated losses	(399)	(3,330)
Total, accumulated losses	(1,021)	(4,653)
Commercial paper
Investments, Fair Value
Less than 12 months, fair value	111,609	172,422
12 months or greater, fair value	0	0
Total, fair value	111,609	172,422
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(113)	(131)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(113)	(131)
Certificates of deposit
Investments, Fair Value
Less than 12 months, fair value	21,474	71,813
12 months or greater, fair value	0	0
Total, fair value	21,474	71,813
Investments, Gross Unrealized Losses
Less than 12 months, accumulated losses	(9)	(15)
12 months or greater, accumulated losses	0	0
Total, accumulated losses	(9)	(15)
U.S. government securities
Cash Equivalents, Fair Value
Less than 12 months, fair value	60,252	338,893
12 months or greater, fair value	0	0
Total, fair value	60,252	338,893
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)
Corporate notes and bonds
Cash Equivalents, Fair Value
Less than 12 months, fair value	12,160
12 months or greater, fair value	0
Total, fair value	12,160
Cash Equivalents, Gross Unrealized Losses
Less than 12 months, accumulated losses	(1)
12 months or greater, accumulated losses	0
Total, accumulated losses	$ (1)