| Cover | 12 Months Ended |
| Dec. 31, 2022 | |
| Document Information [Line Items] | |
| Document Type | DEF 14A |
| Amendment Flag | false |
| Entity Information [Line Items] | |
| Entity Registrant Name | FRANKLIN BSP REALTY TRUST, INC. |
| Entity Central Index Key | 0001562528 |
| Pay vs Performance Disclosure | 12 Months Ended |
| Dec. 31, 2022 USD ($) | |
| Pay vs Performance Disclosure [Table] | |
| Pay vs Performance [Table Text Block] | Pay Versus Performance Table The following table sets forth information concerning the compensation paid to our Chief Executive Officer and to our Chief Operating Officer and Chief Financial Officer (who is our only other NEO) compared to Company performance for the years ended December 31, 2022. We have not presented information for years prior to 2022 because we did not pay our executive officers in any year prior to 2022. Year Summary (1)(2) CAP to (3) Average (1)(2) Average (3) Value of Initial Fixed GAAP Net (5) Distributable (6) TSR (4) Peer (4) 2022 $ 1,164,379 $ 1,128,652 $ 846,820 $ 820,837 $ 85.93 $ 71.69 $ 14,215 $ 116,076 (1) Our CEO during 2022 is Richard J. Byrne. References to “Other NEOs” in this section refer to Jerome S. Baglien, our Chief Operating Officer, Chief Financial Officer and Treasurer, who is our only other NEO. (2) The values reflected in this column reflect the “Total” compensation set forth in the Summary Compensation Table (“SCT”) on page 30. See the footnotes to the SCT for further detail regarding the amounts in this column. (3) Compensation actually paid (“CAP”) is defined by the SEC and is computed in accordance with SEC rules by subtracting the amounts in the “Stock Awards” column of the SCT for each year from the “Total” column of the SCT and then: (i) adding the fair value as of the end of the reported year of all awards granted during the reporting year that are outstanding and unvested as of the end of the reporting year; (ii) adding the amount equal to the change as of the end of the reporting year (from the end of the prior year) in fair value (whether positive or negative) of any awards granted in any prior year that are outstanding and unvested as of the end of the reporting year; (iii) adding, for awards that are granted and vest in the reporting year, the fair value as of the vesting date; (iv) adding the amount equal to the change as of the vesting date (from the end of the prior fiscal year) in fair value (whether positive or negative) of any awards granted in any prior year for which all applicable vesting conditions were satisfied at the end of or during the reporting year; (v) subtracting, for any awards granted in any prior year that are forfeited during the reporting year, the amount equal to the fair value at the end of the prior year; and (vi) adding the value of any dividends (or dividend equivalents) paid in the reporting year on unvested equity awards and the value of accrued dividends (or dividend equivalents) paid on performance awards that vested in the reporting year. The following tables reflect the adjustments made to SCT total compensation to compute CAP for our CEO and average CAP for our other NEOs. CEO SCT Total Comp Minus SCT Equity Plus Value of Plus Dividends on Equals CAP 2022 $ 1,164,379 $ 1,164,379 $ 1,042,176 $ 86,476 $ 1,128,652 Other NEOs (Average) SCT Minus SCT Equity Plus Value of Plus Dividends on Equals CAP 2022 $ 846,820 $ 846,820 $ 757,945 $ 62,892 $ 820,837 (4) Reflects the cumulative TSR of the Company and the Bloomberg REIT Mortgage Index from October 19, 2021 (the date our Common Stock began trading on the NYSE) to December 31, 2022, assuming a $100 investment at the closing price on October 19, 2021 and the reinvestment of all dividends. (5) Amounts in thousands. (6) Please refer to our Form 10-K |
| Company Selected Measure Name | Distributable Earnings |
| Named Executive Officers, Footnote [Text Block] | “Other NEOs” in this section refer to Jerome S. Baglien, our Chief Operating Officer, Chief Financial Officer and Treasurer, who is our only other NEO. |
| Peer Group Issuers, Footnote [Text Block] | Reflects the cumulative TSR of the Company and the Bloomberg REIT Mortgage Index from October 19, 2021 (the date our Common Stock began trading on the NYSE) to December 31, 2022, assuming a $100 investment at the closing price on October 19, 2021 and the reinvestment of all dividends. |
| PEO Total Compensation Amount | $ 1,164,379 |
| PEO Actually Paid Compensation Amount | $ 1,128,652 |
| Adjustment To PEO Compensation, Footnote [Text Block] | CEO SCT Total Comp Minus SCT Equity Plus Value of Plus Dividends on Equals CAP 2022 $ 1,164,379 $ 1,164,379 $ 1,042,176 $ 86,476 $ 1,128,652 |
| Non-PEO NEO Average Total Compensation Amount | $ 846,820 |
| Non-PEO NEO Average Compensation Actually Paid Amount | $ 820,837 |
| Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | Other NEOs (Average) SCT Minus SCT Equity Plus Value of Plus Dividends on Equals CAP 2022 $ 846,820 $ 846,820 $ 757,945 $ 62,892 $ 820,837 |
| Compensation Actually Paid vs. Total Shareholder Return [Text Block] | Relationship of SEC CAP to Performance As discussed in the “Compensation Discussion and Analysis” section above, when issuing equity-based awards, the Compensation Committee considers numerous factors including Company financial and operational performance and peer compensation practices. Thus the Company’s absolute and relative TSR, GAAP net income and Distributable Earnings are generally considered in determining annual grants. Restricted stock unit grants are subject to three-year time vesting. During the period the awards are unvested, the value of the awards will change based on changes in our st ock |
| Compensation Actually Paid vs. Net Income [Text Block] | Relationship of SEC CAP to Performance As discussed in the “Compensation Discussion and Analysis” section above, when issuing equity-based awards, the Compensation Committee considers numerous factors including Company financial and operational performance and peer compensation practices. Thus the Company’s absolute and relative TSR, GAAP net income and Distributable Earnings are generally considered in determining annual grants. Restricted stock unit grants are subject to three-year time vesting. During the period the awards are unvested, the value of the awards will change based on changes in our st ock |
| Compensation Actually Paid vs. Company Selected Measure [Text Block] | Relationship of SEC CAP to Performance As discussed in the “Compensation Discussion and Analysis” section above, when issuing equity-based awards, the Compensation Committee considers numerous factors including Company financial and operational performance and peer compensation practices. Thus the Company’s absolute and relative TSR, GAAP net income and Distributable Earnings are generally considered in determining annual grants. Restricted stock unit grants are subject to three-year time vesting. During the period the awards are unvested, the value of the awards will change based on changes in our st ock |
| Tabular List [Table Text Block] | Financial Performance Measures The most important financial performance measures used by the Company in setting pay-for-performance non-financial Significant Financial Performance Measures Distributable Earnings Stockholder economic returns (defined as changes in GAAP book value per share plus dividends paid) Relative TSR Company TSR |
| Total Shareholder Return Amount | $ 85.93 |
| Peer Group Total Shareholder Return Amount | 71.69 |
| Net Income (Loss) | $ 14,215,000 |
| Company Selected Measure Amount | 116,076,000 |
| PEO Name | Richard J. Byrne |
| Measure [Axis]: 1 | |
| Pay vs Performance Disclosure [Table] | |
| Measure Name | Distributable Earnings |
| Measure [Axis]: 2 | |
| Pay vs Performance Disclosure [Table] | |
| Measure Name | Stockholder economic returns (defined as changes in GAAP book value per share plus dividends paid) |
| Measure [Axis]: 3 | |
| Pay vs Performance Disclosure [Table] | |
| Measure Name | Relative TSR |
| Measure [Axis]: 4 | |
| Pay vs Performance Disclosure [Table] | |
| Measure Name | Company TSR |
| PEO [Member] | Equity Awards [Member] | |
| Pay vs Performance Disclosure [Table] | |
| Adjustment to Compensation Amount | $ 1,164,379 |
| PEO [Member] | Value Of New Unvested Awards [Member] | |
| Pay vs Performance Disclosure [Table] | |
| Adjustment to Compensation Amount | 1,042,176 |
| PEO [Member] | Dividends On Unvested Awards [Member] | |
| Pay vs Performance Disclosure [Table] | |
| Adjustment to Compensation Amount | 86,476 |
| Non-PEO NEO [Member] | Equity Awards [Member] | |
| Pay vs Performance Disclosure [Table] | |
| Adjustment to Compensation Amount | 846,820 |
| Non-PEO NEO [Member] | Value Of New Unvested Awards [Member] | |
| Pay vs Performance Disclosure [Table] | |
| Adjustment to Compensation Amount | 757,945 |
| Non-PEO NEO [Member] | Dividends On Unvested Awards [Member] | |
| Pay vs Performance Disclosure [Table] | |
| Adjustment to Compensation Amount | $ 62,892 |
