| Document and Entity Information | Oct. 29, 2020 |
| Entity Addresses [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Oct. 29, 2020 |
| Entity Registrant Name | Bellicum Pharmaceuticals, Inc. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-36783 |
| Entity Tax Identification Number | 20-1450200 |
| Entity Address, Address Line One | 2710 Reed Road |
| Entity Address, Address Line Two | Ste. 160 |
| Entity Address, City or Town | Houston |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77051 |
| City Area Code | 832 |
| Local Phone Number | 384-1100 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | BLCM |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001358403 |
| Amendment Flag | false |
| Security Exchange Name | NASDAQ |
| Former Address | |
| Entity Addresses [Line Items] | |
| Entity Address, Address Line One | 2130 W. Holcombe Blvd. |
| Entity Address, Address Line Two | Ste. 800 |
| Entity Address, City or Town | Houston |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 77030 |
