The initial exercise period of the class of warrant or right.

No definition available.

Name:	mbrx_ClassOfWarrantOrRightInitialExercisePeriod
Namespace Prefix:	mbrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of warrants or rights vested and exercisable.

+ References

No definition available.

+ Details

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Namespace Prefix:	mbrx_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The threshold amount of research and development expenditures for warrant or right to vest.

+ References

No definition available.

+ Details

Name:	mbrx_ClassOfWarrantOrRightVestingContingencyResearchAndDevelopmentExpendituresThreshold
Namespace Prefix:	mbrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

No definition available.

+ Details

Name:	mbrx_SharebasedPaymentArrangementNonvestedAwardCostNotYetRecognizedAmount
Namespace Prefix:	mbrx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=122041274&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

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

- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21475-112644

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Period between issuance and expiration of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
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- Details

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- Details

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Namespace Prefix:
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- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=mbrx_OppenheimerCoUnderwriterWarrantMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_ClassOfWarrantOrRightAxis=mbrx_EquityClassifiedWarrantsMember
Namespace Prefix:
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- Details

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Note 5 - Warrants (Details Textual) - USD ($)	1 Months Ended	12 Months Ended
Note 5 - Warrants (Details Textual) - USD ($)	Feb. 28, 2020	Dec. 31, 2021	Dec. 31, 2020	Aug. 31, 2021	Apr. 30, 2021	Apr. 30, 2020
Share-based Payment Arrangement, Expense		$ 2,373,000	$ 1,680,000
Warrants Issued in June 2018 and Expiring December 22, 2023 [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		118,372
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 12.12
Warrants Issued in June 2018 and Expiring June 21, 2023 [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		5,464
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 13.92
Warrants Issued in July 2017 for Consulting with Exercise Price of 14.46 [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		16,667
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 14.46
Warrants Issued in July 2017 for Consulting with Exercise Price 18.00 [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		8,334
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)		$ 18.00
Warrants Issued in Connection with the February 2020 Stock Offering [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	937,501
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 6.30
Class of Warrant or Right, Initial Exercise Period (Month)	6 months
Warrants and Rights Outstanding, Term (Year)	5 years
Oppenheimer Co, Underwriter Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)	87,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 6.30
Equity Classified Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)		396,502	109,639	250,000	71,500
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 3.08	$ 3.63
Warrants and Rights Outstanding, Term (Year)				10 years	5 years
Class of Warrant or Right, Vested and Exercisable (in shares)		186,560	85,472
Share-based Payment Arrangement, Expense		$ 516,000	$ 5,000
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount		$ 548,000
Warrants Issued in December 2020 for Consulting [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			8,334
Warrants Issued in April 2020 for Consulting [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)						16,667
Class of Warrant or Right, Vesting Contingency, Research and Development Expenditures Threshold						$ 10,000,000.0