{"cik":728385,"taxonomy":"us-gaap","tag":"LesseeOperatingLeaseLiabilityUndiscountedExcessAmount","label":"Lessee, Operating Lease, Liability, Undiscounted Excess Amount","description":"Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.","entityName":"BIRCHTECH CORP.","units":{"USD":[{"end":"2026-03-31","val":76764,"accn":"0001477932-26-003054","fy":2026,"fp":"Q1","form":"10-Q","filed":"2026-05-13","frame":"CY2026Q1I"},{"end":"2026-06-30","val":68016,"accn":"0001477932-26-004988","fy":2026,"fp":"Q2","form":"10-Q","filed":"2026-08-13","frame":"CY2026Q2I"}]}}