Short-Term Investments - Schedule of Fair Values and Gross Unrealized Loss Position of Available-for-Sale Securities Aggregated by Investment Category (Details) - USD ($) $ in Thousands	Apr. 30, 2026	Jan. 31, 2026
Debt Securities, Available-for-Sale [Line Items]
12 months or less, Fair value	$ 3,038,325	$ 677,866
12 months or less, Gross unrealized losses	(18,282)	(1,477)
Greater than 12 months, Fair value	8,670	9,139
Greater than 12 months, Gross unrealized losses	(58)	(59)
Certificates of deposit
Debt Securities, Available-for-Sale [Line Items]
12 months or less, Fair value	27,669	27,690
12 months or less, Gross unrealized losses	(41)	(20)
Greater than 12 months, Fair value	0	0
Greater than 12 months, Gross unrealized losses	0	0
Asset-backed securities
Debt Securities, Available-for-Sale [Line Items]
12 months or less, Fair value	0	4,091
12 months or less, Gross unrealized losses	0	(80)
Greater than 12 months, Fair value	622	1,090
Greater than 12 months, Gross unrealized losses	(48)	(51)
Commercial paper
Debt Securities, Available-for-Sale [Line Items]
12 months or less, Fair value	34,796	9,960
12 months or less, Gross unrealized losses	(3)	(1)
Greater than 12 months, Fair value	0	0
Greater than 12 months, Gross unrealized losses	0	0
Corporate notes and bonds
Debt Securities, Available-for-Sale [Line Items]
12 months or less, Fair value	1,604,542	425,464
12 months or less, Gross unrealized losses	(11,568)	(950)
Greater than 12 months, Fair value	0	0
Greater than 12 months, Gross unrealized losses	0	0
Foreign government bonds
Debt Securities, Available-for-Sale [Line Items]
12 months or less, Fair value	111,351	69,877
12 months or less, Gross unrealized losses	(636)	(68)
Greater than 12 months, Fair value	8,048	8,049
Greater than 12 months, Gross unrealized losses	(10)	(8)
Municipal securities
Debt Securities, Available-for-Sale [Line Items]
12 months or less, Fair value	11,005	580
12 months or less, Gross unrealized losses	(72)	0
Greater than 12 months, Fair value	0	0
Greater than 12 months, Gross unrealized losses	0	0
U.S. treasury securities
Debt Securities, Available-for-Sale [Line Items]
12 months or less, Fair value	1,248,962	140,204
12 months or less, Gross unrealized losses	(5,962)	(358)
Greater than 12 months, Fair value	0	0
Greater than 12 months, Gross unrealized losses	$ 0	$ 0

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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