v3.26.1

Condensed Consolidated Statements of Operations and Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
SPN [Member]
Reimbursement received	$ 0	$ 6,309

X

- Definition

Reimbursement received from related party.

+ References

No definition available.

+ Details

Name:	mcrb_ReimbursementReceivedFromRelatedParty
Namespace Prefix:	mcrb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=mcrb_SpnMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: