Segment Reporting - Schedule of Operations by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Interest income	$ 430,280	$ 526,076	$ 552,506
Mortgage servicing rights	28,570	0	0
Servicing revenue, net	12,516	0	0
Revenue from real estate owned	29,633	22,849	17,021
Interest expense	(288,327)	(338,471)	(305,577)
Compensation and benefits	(53,739)	0	0
Administrative services expenses	(13,346)	(9,707)	(14,440)
Depreciation and amortization	(9,593)	(5,630)	(7,128)
Operating expenses	(100,574)	(62,934)	(61,493)
Other segment items	48,665	(39,780)	(36,380)
Net income/(loss)	84,085	92,403	144,509
Total Assets	6,057,250	6,002,386	5,955,180
Real Estate Debt and Other Real Estate Investments
Segment Reporting Information [Line Items]
Interest income	407,155	519,342	547,439
Mortgage servicing rights	0	0	0
Servicing revenue, net	0	0	0
Revenue from real estate owned	0	0	0
Interest expense	(265,396)	(335,718)	(302,445)
Compensation and benefits	0	0	0
Administrative services expenses	(8,551)	(4,582)	(8,313)
Depreciation and amortization	0	0	0
Operating expenses	(48,959)	(41,284)	(52,115)
Other segment items	(6,296)	(43,254)	(28,649)
Net income/(loss)	77,953	94,504	155,917
Total Assets	4,797,877	5,466,780	5,618,320
Agency Business
Segment Reporting Information [Line Items]
Interest income	12,797	0	0
Mortgage servicing rights	28,570	0	0
Servicing revenue, net	12,516	0	0
Revenue from real estate owned	20	0	0
Interest expense	(13,898)	0	0
Compensation and benefits	(53,739)	0	0
Administrative services expenses	(609)	0	0
Depreciation and amortization	(4,168)	0	0
Operating expenses	(13,652)	0	0
Other segment items	44,255	0	0
Net income/(loss)	12,092	0	0
Total Assets	857,562	0	0
Conduit
Segment Reporting Information [Line Items]
Interest income	6,523	5,553	2,244
Mortgage servicing rights	0	0	0
Servicing revenue, net	0	0	0
Revenue from real estate owned	0	0	0
Interest expense	(660)	(721)	(1,150)
Compensation and benefits	0	0	0
Administrative services expenses	(4,186)	(5,125)	(6,127)
Depreciation and amortization	0	0	0
Operating expenses	(6,381)	(4,930)	(5,412)
Other segment items	15,110	11,605	(80)
Net income/(loss)	10,406	6,382	(10,525)
Total Assets	33,015	128,430	66,503
Real Estate Owned
Segment Reporting Information [Line Items]
Interest income	3,805	1,181	2,823
Mortgage servicing rights	0	0	0
Servicing revenue, net	0	0	0
Revenue from real estate owned	29,613	22,849	17,021
Interest expense	(8,373)	(2,032)	(1,982)
Compensation and benefits	0	0	0
Administrative services expenses	0	0	0
Depreciation and amortization	(5,425)	(5,630)	(7,128)
Operating expenses	(31,582)	(16,720)	(3,966)
Other segment items	(4,404)	(8,131)	(7,651)
Net income/(loss)	(16,366)	(8,483)	(883)
Total Assets	$ 368,796	$ 407,176	$ 270,357

Franklin BSP Realty Trust, Inc. 10-K