Discloses the expected amount of annualized savings resulting from restructuring activities.

No definition available.

Name:	imbi_RestructuringandRelatedCostExpectedAnnualizedSavings
Namespace Prefix:	imbi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow from the additional capital contribution to the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585

+ Details

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

- Definition

The cash inflow associated with the amount received from entity's raising of capital via private rather than public placement.

+ References

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=imbi_Q1Fiscal2020RestructuringPlansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Credit Agreements - Cash Requirements (Details) - USD ($)					3 Months Ended				6 Months Ended	12 Months Ended
	Aug. 28, 2020	Aug. 01, 2020	Apr. 16, 2020	May 02, 2019	May 01, 2021	Oct. 31, 2020	May 02, 2020	May 04, 2019	Aug. 01, 2020	Jan. 30, 2021	Feb. 01, 2020
Debt Instrument [Line Items]
Proceeds from issuance of common stock and warrants	$ 15,833,000				$ 21,200,000	$ 15,800,000			$ 4,000,000.0	$ 20,043,000	$ 6,000,000
Gross proceeds from private placement securities issuance		$ 2,500,000	$ 1,500,000	$ 6,000,000.0				$ 6,000,000.0	$ 4,000,000
Fiscal 2019 Restructuring Plans [Member]
Debt Instrument [Line Items]
Restructuring and Related Cost, Expected Annualized Savings											$ 22,000,000
Q1 Fiscal 2020 Restructuring Plans [Member]
Debt Instrument [Line Items]
Restructuring and Related Cost, Expected Annualized Savings							$ 16,000,000