Short-Term Investments - Schedule of Fair Values and Gross Unrealized Loss Position of Available-for-Sale Securities Aggregated by Investment Category (Detail) - USD ($) $ in Thousands	Jul. 31, 2022	Jan. 31, 2022
Certificates of deposits
Schedule of Available-for-sale Securities [Line Items]
Held for less than 12 months, Fair value	$ 60,495	$ 5,985
Held for less than 12 months, Gross unrealized losses	(214)	(15)
Held for more than 12 months, Fair value	0
Held for more than 12 months, Gross unrealized losses	0
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Held for less than 12 months, Fair value	282,437	177,056
Held for less than 12 months, Gross unrealized losses	(3,928)	(1,432)
Held for more than 12 months, Fair value	6,188
Held for more than 12 months, Gross unrealized losses	(161)
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Held for less than 12 months, Fair value	168,390	17,190
Held for less than 12 months, Gross unrealized losses	(636)	(2)
Held for more than 12 months, Fair value	0
Held for more than 12 months, Gross unrealized losses	0
Corporate notes and bonds
Schedule of Available-for-sale Securities [Line Items]
Held for less than 12 months, Fair value	766,929	571,099
Held for less than 12 months, Gross unrealized losses	(14,251)	(5,856)
Held for more than 12 months, Fair value	64,854
Held for more than 12 months, Gross unrealized losses	(2,199)
Foreign government bonds
Schedule of Available-for-sale Securities [Line Items]
Held for less than 12 months, Fair value	16,730	19,594
Held for less than 12 months, Gross unrealized losses	(409)	(179)
Held for more than 12 months, Fair value	0
Held for more than 12 months, Gross unrealized losses	0
U.S. agency obligations
Schedule of Available-for-sale Securities [Line Items]
Held for less than 12 months, Fair value	22,286	24,725
Held for less than 12 months, Gross unrealized losses	(620)	(254)
Held for more than 12 months, Fair value	2,075
Held for more than 12 months, Gross unrealized losses	(5)
U.S. treasury securities
Schedule of Available-for-sale Securities [Line Items]
Held for less than 12 months, Fair value	265,627	247,509
Held for less than 12 months, Gross unrealized losses	(4,330)	$ (1,756)
Held for more than 12 months, Fair value	7,249
Held for more than 12 months, Gross unrealized losses	$ (244)

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27337-111563

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 55
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456

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Amount of accumulated unrealized loss on 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 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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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 less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI https://asc.fasb.org/extlink&oid=126970911&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 55
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456

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Amount of accumulated unrealized loss on 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 less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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