Fair Value Measurements - Estimated Fair Value and Carrying Value of Notes (Detail) - USD ($) $ in Thousands	Jul. 31, 2021	Jan. 30, 2021
Convertible senior notes due 2023
Fair Value Balance Sheet Grouping Financial Statement Captions
Convertible senior notes, Fair Value	$ 287,314	$ 301,794
Convertible senior notes, Carrying Value	267,905	287,936
Convertible senior notes due 2024
Fair Value Balance Sheet Grouping Financial Statement Captions
Convertible senior notes, Fair Value	314,630	286,161
Convertible senior notes, Carrying Value	$ 292,437	$ 284,182

Including the current and noncurrent portions, carrying value as of the balance sheet date of a written promise to pay a note, initially due after one year or beyond the operating cycle if longer, which can be exchanged for a specified amount of one or more securities (typically common stock), at the option of the issuer or the holder.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 210
-Section S99
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-Subparagraph (SX 210.6-04(13))
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
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-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant