Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12355-112629

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=117329964&loc=d3e12317-112629

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Convertible Senior Notes - Calculation of Gain on Extinguishment of Convertible Senior Notes (Details) - USD ($) $ in Thousands		9 Months Ended
	Jun. 05, 2020	Oct. 31, 2020	Oct. 31, 2019
Extinguishment of Convertible Senior Notes [Line Items]
Gain from the 2023 Notes Partial Repurchase		$ 6,952	$ 0
Convertible Senior Notes \| 2023 Notes, Partial repurchase
Extinguishment of Convertible Senior Notes [Line Items]
Net carrying amount of the liability component associated with the 2023 Notes Partial Repurchase	$ 414,401
Less: Cash consideration allocated to the liability component	(407,449)
Gain from the 2023 Notes Partial Repurchase	$ 6,952