{"cik":1622229,"taxonomy":"us-gaap","tag":"LongTermDebt","label":"Long-term Debt","description":"Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.","entityName":"Cogent Biosciences, Inc.","units":{"USD":[{"end":"2025-06-30","val":43949000,"accn":"0000950170-25-102440","fy":2025,"fp":"Q2","form":"10-Q","filed":"2025-08-05","frame":"CY2025Q2I"},{"end":"2025-09-30","val":44250000,"accn":"0001193125-25-272334","fy":2025,"fp":"Q3","form":"10-Q","filed":"2025-11-07","frame":"CY2025Q3I"},{"end":"2025-12-31","val":222895000,"accn":"0001193125-26-053334","fy":2025,"fp":"FY","form":"10-K","filed":"2026-02-17","frame":"CY2025Q4I"},{"end":"2026-03-31","val":223173000,"accn":"0001193125-26-205170","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-05-05","frame":"CY2026Q1I"},{"end":"2026-06-30","val":223457000,"accn":"0001193125-26-342393","fy":2026,"fp":"Q2","form":"10-Q","filed":"2026-08-10","frame":"CY2026Q2I"}]}}