Balance Sheet Components - Schedule of Other Long-Term Assets (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
Jan. 31, 2022	Jan. 31, 2021
Property Plant And Equipment [Line Items]
Capitalized stock-based compensation expenses	$ 2.8	$ 2.8
On-premises software
Property Plant And Equipment [Line Items]
Accumulated amortization of capitalized software costs	7.0	3.4
Amortization expense related to capitalized software	3.6	3.4
Internally Developed Software
Property Plant And Equipment [Line Items]
Accumulated amortization of capitalized software costs	16.4	7.8
Amortization expense related to capitalized software	$ 8.6	$ 6.1

Capitalized stock-based compensation expense.

No definition available.

Name:	box_CapitalizedStockBasedCompensationExpense
Namespace Prefix:	box_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

For each balance sheet presented, the amount of accumulated amortization for capitalized computer software costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

+ Details

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

- Definition

Amount of expense for amortization of capitalized computer software costs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128462-111756

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6501960&loc=d3e128487-111756

+ Details

Name:	us-gaap_CapitalizedComputerSoftwareAmortization1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=box_OnPremisesSoftwareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=box_InternallyDevelopedSoftwareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: