Short-Term Investments - Schedule of Short-Term Investments (Details) - USD ($) $ in Thousands	Apr. 30, 2024	Jan. 31, 2024
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	$ 3,591,722	$ 3,321,633
Gross unrealized gains	1,314	13,892
Gross unrealized losses	(25,195)	(11,256)
Estimated fair value	3,567,841	3,324,269
Certificates of deposits
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	98,650	94,210
Gross unrealized gains	23	87
Gross unrealized losses	(55)	(14)
Estimated fair value	98,618	94,283
Asset-backed securities
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	659,618	605,852
Gross unrealized gains	571	2,916
Gross unrealized losses	(3,834)	(1,787)
Estimated fair value	656,355	606,981
Commercial paper
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	284,131	144,218
Gross unrealized gains	6	47
Gross unrealized losses	(119)	(20)
Estimated fair value	284,018	144,245
Corporate notes and bonds
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	1,719,063	1,581,382
Gross unrealized gains	673	8,835
Gross unrealized losses	(12,669)	(5,188)
Estimated fair value	1,707,067	1,585,029
Foreign government bonds
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	54,834	50,180
Gross unrealized gains	0	206
Gross unrealized losses	(456)	(180)
Estimated fair value	54,378	50,206
Municipal securities
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	76,780	79,404
Gross unrealized gains	41	301
Gross unrealized losses	(473)	(231)
Estimated fair value	76,348	79,474
U.S. agency obligations
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	55,920	49,372
Gross unrealized gains	0	232
Gross unrealized losses	(211)	(12)
Estimated fair value	55,709	49,592
U.S. treasury securities
Debt Securities, Available-for-Sale [Line Items]
Amortized cost	642,726	717,015
Gross unrealized gains	0	1,268
Gross unrealized losses	(7,378)	(3,824)
Estimated fair value	$ 635,348	$ 714,459

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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