Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended							9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022		Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022		Dec. 31, 2022	Dec. 31, 2021
Segment Reporting [Abstract]
Income Tax Expense (Benefit)	$ 224			$ (81)	[1]			$ 328	$ (14,867)	[1]
Segment Reporting Information [Line Items]
Interest income	96,216			78,592	[1]			271,482	192,388	[1]
Interest expense	(68,702)			(42,080)	[1]			(191,752)	(82,121)	[1]
Noninterest Income	26,220			(26,348)	[1]			112,559	(121,398)	[1]
Operating Expenses	39,452			14,463	[1]			119,986	47,132	[1]
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	14,282			(4,299)	[1]			72,303	(58,263)	[1]
Earnings (losses) from investments in unconsolidated entities	(978)			(25,513)	[1]			(3,403)	(54,284)	[1]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	13,080	$ 10,739	$ 44,753	(29,731)	[1]	$ (61,451)	$ (6,498)	68,572	(97,680)	[1]
Net income (loss) attributable to non-controlling interests	509			(264)	[1]			3,090	(1,075)	[1]
Dividends on preferred stock	5,980			3,823	[1]			17,077	11,468	[1]
Net income (loss) attributable to common stockholders	6,591			(33,290)	[1]			48,405	(108,073)	[1]
Depreciation	149							859
Total Assets	14,445,041							14,445,041			$ 14,085,886
Liabilities	13,107,624							13,107,624			12,865,000
Total Equity	1,337,417	$ 1,344,657	$ 1,374,763	1,180,629		$ 1,234,455	$ 1,322,938	1,337,417	1,180,629		1,220,886	$ 1,323,556
Longbridge Segment
Segment Reporting [Abstract]
Income Tax Expense (Benefit)	0							0
Segment Reporting Information [Line Items]
Interest income	5,190							11,862
Interest expense	(7,540)							(18,003)
Noninterest Income	31,752							95,779
Operating Expenses	25,319							76,583
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	4,083							13,055
Earnings (losses) from investments in unconsolidated entities	0							0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	4,083							13,055
Net income (loss) attributable to non-controlling interests	(12)							(35)
Dividends on preferred stock	0							0
Net income (loss) attributable to common stockholders	4,095							13,090
Depreciation	149							859
Total Assets	8,822,286							8,822,286			8,227,509
Liabilities	8,565,506							8,565,506			8,092,313
Total Equity	256,780							256,780			135,196
Investment Portfolio Segment
Segment Reporting [Abstract]
Income Tax Expense (Benefit)	0			0				0	0
Segment Reporting Information [Line Items]
Interest income	89,445			77,887				254,932	191,329
Interest expense	(58,045)			(38,121)				(164,388)	(72,432)
Noninterest Income	(11,969)			(24,514)				12,314	(118,832)
Operating Expenses	3,771			7,120				11,140	20,187
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	15,660			8,132				91,718	(20,122)
Earnings (losses) from investments in unconsolidated entities	(978)			(25,513)				(3,403)	(54,284)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	14,682			(17,381)				88,315	(74,406)
Net income (loss) attributable to non-controlling interests	438			156				2,522	287
Dividends on preferred stock	0			0				0	0
Net income (loss) attributable to common stockholders	14,244			(17,537)				85,793	(74,693)
Depreciation	0							0
Total Assets	5,443,151							5,443,151			5,635,657
Liabilities	4,246,945							4,246,945			4,499,669
Total Equity	1,196,206							1,196,206			1,135,988
Corporate and Other
Segment Reporting [Abstract]
Income Tax Expense (Benefit)	224			(81)				328	(14,867)
Segment Reporting Information [Line Items]
Interest income	1,581			705				4,688	1,059
Interest expense	(3,117)			(3,959)				(9,361)	(9,689)
Noninterest Income	6,437			(1,834)				4,466	(2,566)
Operating Expenses	10,362			7,343				32,263	26,945
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest	(5,461)			(12,431)				(32,470)	(38,141)
Earnings (losses) from investments in unconsolidated entities	0			0				0	0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(5,685)			(12,350)				(32,798)	(23,274)
Net income (loss) attributable to non-controlling interests	83			(420)				603	(1,362)
Dividends on preferred stock	5,980			3,823				17,077	11,468
Net income (loss) attributable to common stockholders	(11,748)			$ (15,753)				(50,478)	$ (33,380)
Depreciation	0							0
Total Assets	179,604							179,604			222,720
Liabilities	295,173							295,173			273,018
Total Equity	$ (115,569)							$ (115,569)			$ (50,298)

[1] Conformed to current period presentation.