Equity-based Compensation and Equity Incentive Plans - Schedule of Weighted Average Assumption Used Black-Scholes Option-pricing Model for Stock Options Issued to Employees and Non-employees (Detail) - Employees and Nonemployees - 2015 and 2017 Plan	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	5 years 7 months 6 days	6 years 2 months 12 days
Weighted-average, risk-free interest rate	3.90%	3.70%
Expected volatility	92.00%	82.40%
Dividend yield	0.00%	0.00%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

SYNLOGIC, INC. 10-K