{"cik":1503802,"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":"Karyopharm Therapeutics Inc.","units":{"USD":[{"end":"2021-12-31","val":169293000,"accn":"0000950170-22-002548","fy":2021,"fp":"FY","form":"10-K","filed":"2022-03-01","frame":"CY2021Q4I"}]}}