| Document and Entity Information | Nov. 12, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 12, 2021 |
| Entity Registrant Name | BROADWAY FINANCIAL CORP \DE\ |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-39043 |
| Entity Tax Identification Number | 95-4547287 |
| Entity Address, Address Line One | 5055 WILSHIRE BLVD STE 500 |
| Entity Address, City or Town | LOS ANGELES |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 90036 |
| City Area Code | 323 |
| Local Phone Number | 634-1700 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001001171 |
| Title of 12(b) Security | Class A Common Stock, par value $0.01 per share (including attached preferred stock purchase rights) |
| Trading Symbol | BYFC |
| Security Exchange Name | NASDAQ |
