Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying consolidated financial statements and the related disclosures as of March 31, 2024 and for the three months ended March 31, 2024 and 2023 are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States (GAAP) and the rules and regulations of the SEC for interim financial statements. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. These interim consolidated financial statements should be read in conjunction with the Company’s 2023 and 2022 audited consolidated financial statements and notes included in the 2023 Annual Report. The consolidated balance sheet as of December 31, 2023 included herein was derived from the audited financial statements as of that date but does not include all disclosures including notes required by GAAP for complete financial statements. In the opinion of management, the unaudited interim consolidated financial statements reflect all adjustments, consisting of normal and recurring adjustments, necessary for the fair presentation of the Company’s financial position and results of operations for the three months ended March 31, 2024 and 2023. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the year ending December 31, 2024 or any other interim period or future year or period.
Principles of Consolidation	Principles of Consolidation The accompanying consolidated financial statements include the accounts of Synlogic and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (FASB) or other accounting standard setting boards that the Company adopts as of the effective date. Unless otherwise discussed below, recently issued pronouncements that are or will be applicable to the Company did not have, or are not expected to have, a material impact on the Company’s present or future financial statements.

Disclosure of accounting policy regarding (1) the principles it follows in consolidating or combining the separate financial statements, including the principles followed in determining the inclusion or exclusion of subsidiaries or other entities in the consolidated or combined financial statements and (2) its treatment of interests (for example, common stock, a partnership interest or other means of exerting influence) in other entities, for example consolidation or use of the equity or cost methods of accounting. The accounting policy may also address the accounting treatment for intercompany accounts and transactions, noncontrolling interest, and the income statement treatment in consolidation for issuances of stock by a subsidiary.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483426/235-10-50-4

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481203/810-10-50-1

Name:	us-gaap_ConsolidationPolicyTextBlock
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration