Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

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

SUBSEQUENT EVENTS (Details) - USD ($) $ in Millions	Jan. 28, 2025	Apr. 02, 2024
Segment Discontinued Operations \| I-Mab Shanghai \| I-Mab Hangzhou
Subsequent Event [Line Items]
Percentage of transfer of outstanding equity interest		100.00%
Subsequent Event
Subsequent Event [Line Items]
Percentage of reduction of workforce	27.00%
Employee severance payments, benefits and termination costs	$ 0.8