v3.23.3

Milestones and Research Agreements - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Milestones And Research Agreements [Abstract]
Potential milestone payment	$ 0.8
Milestone payment, diligence maintenance fees	$ 0.1	$ 0.1

X

- Definition

Milestone payment, diligence maintenance fees.

+ References

No definition available.

+ Details

Name:	asmb_MilestonePaymentDiligenceMaintenanceFees
Namespace Prefix:	asmb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Milestones and Research Agreements

+ References

No definition available.

+ Details

Name:	asmb_MilestonesAndResearchAgreementsAbstract
Namespace Prefix:	asmb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(17))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(25))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

+ Details

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