Segment Information - Schedule of Business Segment Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2026		Jun. 30, 2025	Jun. 30, 2026		Jun. 30, 2025	Dec. 31, 2025	[1]
Segment Reporting [Line Items]
Interest income	$ 385,224		$ 284,336	$ 742,143		$ 556,430
Interest expense	(353,153)		(270,502)	(675,355)		(514,654)
Net interest income (expense)	32,071		13,834	66,788		41,776
Non-Interest Income
Mortgage banking activities, net, excluding risk management derivatives	62,604		(7,278)	125,950		7,933
Risk management derivatives (losses) gains, net	(30,533)		48,135	(61,915)		65,977
Total Mortgage banking activities, net	32,071		40,857	64,035		73,910
Investment fair value changes, net	(22,523)		(84,704)	(45,722)		(89,892)
HEI income, net	2,798		(12,899)	9,907		(2,733)
Servicing income, net	2,648		1,608	10,669		5,015
Fee income (loss), net	2,960		2,209	5,846		4,560
Other income (loss), net	5,985		352	8,422		1,902
Realized gains, net	0		640	0		1,207
Total non-interest income (loss), net	23,939		(51,937)	53,157		(6,031)
General and administrative expenses	(38,198)		(36,983)	(87,556)		(74,454)
Portfolio management costs	(7,030)		(10,028)	(15,759)		(16,519)
Loan acquisition costs	(5,990)		(4,781)	(12,719)		(8,349)
Other expenses	(4,747)		(4,035)	(11,872)		(7,944)
Benefit from (Provision for) income taxes	(1,145)		(4,562)	1,358		(10,824)
Net (Loss) Income	(1,100)		(98,492)	(6,603)		(82,345)
Dividends on preferred stock	(1,758)		(1,757)	(3,508)		(3,507)
Net (Loss) Income (Related) Available To Common Stockholders	(2,858)		(100,249)	(10,111)		(85,852)
Total Assets	28,818,131	[1]	21,333,020	28,818,131	[1]	21,333,020	$ 23,701,114
Investment fair value changes, net, excluding risk management derivatives
Non-Interest Income
Investment fair value changes, net	13,801		(101,696)	28,876		(127,515)
Risk management derivatives gains (losses), net
Non-Interest Income
Investment fair value changes, net	(36,324)		16,992	(74,598)		37,623
Sequoia
Non-Interest Income
Total Mortgage banking activities, net	12,944		24,313	34,995		46,232
Aspire
Non-Interest Income
Total Mortgage banking activities, net	9,199		83	11,883		315
CoreVest
Non-Interest Income
Total Mortgage banking activities, net	9,928		16,461	17,157		27,363
Fee income (loss), net	3,000		2,000	6,000		5,000
Operating Segments | Sequoia
Segment Reporting [Line Items]
Interest income	58,354		35,503	119,660		67,142
Interest expense	(31,080)		(24,915)	(67,417)		(41,933)
Net interest income (expense)	27,274		10,588	52,243		25,209
Non-Interest Income
Mortgage banking activities, net, excluding risk management derivatives	58,697		(23,756)	116,659		(22,624)
Risk management derivatives (losses) gains, net	(45,753)		48,069	(81,664)		68,856
Total Mortgage banking activities, net	12,944		24,313	34,995		46,232
Investment fair value changes, net	0		0	0		0
HEI income, net	0		0	0		0
Servicing income, net	0		0	0		0
Fee income (loss), net	0		0	0		0
Other income (loss), net	0		0	0		0
Realized gains, net	0		0	0		0
Total non-interest income (loss), net	12,944		24,313	34,995		46,232
General and administrative expenses	(6,134)		(6,015)	(13,183)		(11,433)
Portfolio management costs	0		0	0		0
Loan acquisition costs	(2,098)		(1,267)	(4,939)		(2,338)
Other expenses	0		0	0		0
Benefit from (Provision for) income taxes	134		(9,310)	1,379		(16,502)
Net (Loss) Income	32,120		18,309	70,495		41,168
Dividends on preferred stock	(519)		(483)	(1,063)		(889)
Net (Loss) Income (Related) Available To Common Stockholders	31,601		17,826	69,432		40,279
Total Assets	2,236,378		1,551,366	2,236,378		1,551,366
Operating Segments | Sequoia | Investment fair value changes, net, excluding risk management derivatives
Non-Interest Income
Investment fair value changes, net	0		0	0		0
Operating Segments | Sequoia | Risk management derivatives gains (losses), net
Non-Interest Income
Investment fair value changes, net	0		0	0		0
Operating Segments | Aspire
Segment Reporting [Line Items]
Interest income	18,109		1,518	36,517		1,562
Interest expense	(14,548)		(1,587)	(29,314)		(1,814)
Net interest income (expense)	3,561		(69)	7,203		(252)
Non-Interest Income
Mortgage banking activities, net, excluding risk management derivatives	(6,039)		1,124	(7,583)		1,356
Risk management derivatives (losses) gains, net	15,238		(1,041)	19,466		(1,041)
Total Mortgage banking activities, net	9,199		83	11,883		315
Investment fair value changes, net	0		0	0		0
HEI income, net	0		0	0		0
Servicing income, net	30		0	30		0
Fee income (loss), net	0		0	0		0
Other income (loss), net	0		0	0		0
Realized gains, net	0		0	0		0
Total non-interest income (loss), net	9,229		83	11,913		315
General and administrative expenses	(2,826)		(1,190)	(5,292)		(2,118)
Portfolio management costs	0		0	0		0
Loan acquisition costs	(1,067)		0	(2,113)		0
Other expenses	0		0	0		0
Benefit from (Provision for) income taxes	(1,419)		21	(1,761)		(49)
Net (Loss) Income	7,478		(1,155)	9,950		(2,104)
Dividends on preferred stock	(170)		(28)	(374)		(45)
Net (Loss) Income (Related) Available To Common Stockholders	7,308		(1,183)	9,576		(2,149)
Total Assets	835,233		137,751	835,233		137,751
Operating Segments | Aspire | Investment fair value changes, net, excluding risk management derivatives
Non-Interest Income
Investment fair value changes, net	0		0	0		0
Operating Segments | Aspire | Risk management derivatives gains (losses), net
Non-Interest Income
Investment fair value changes, net	0		0	0		0
Operating Segments | CoreVest
Segment Reporting [Line Items]
Interest income	3,491		3,737	7,683		8,131
Interest expense	(2,209)		(2,841)	(4,292)		(5,851)
Net interest income (expense)	1,282		896	3,391		2,280
Non-Interest Income
Mortgage banking activities, net, excluding risk management derivatives	9,946		15,354	16,874		29,201
Risk management derivatives (losses) gains, net	(18)		1,107	283		(1,838)
Total Mortgage banking activities, net	9,928		16,461	17,157		27,363
Investment fair value changes, net	(38)		0	(303)		0
HEI income, net	0		0	0		0
Servicing income, net	0		0	0		0
Fee income (loss), net	2,496		2,782	5,323		5,861
Other income (loss), net	(182)		715	407		2,397
Realized gains, net	0		0	0		0
Total non-interest income (loss), net	12,204		19,958	22,584		35,621
General and administrative expenses	(7,679)		(10,218)	(20,667)		(20,815)
Portfolio management costs	0		0	0		0
Loan acquisition costs	(2,825)		(3,514)	(5,667)		(6,011)
Other expenses	(2,011)		(2,203)	(4,021)		(4,405)
Benefit from (Provision for) income taxes	285		278	2,346		927
Net (Loss) Income	1,256		5,197	(2,034)		7,597
Dividends on preferred stock	(89)		(101)	(176)		(168)
Net (Loss) Income (Related) Available To Common Stockholders	1,167		5,096	(2,210)		7,429
Total Assets	320,658		301,743	320,658		301,743
Operating Segments | CoreVest | Investment fair value changes, net, excluding risk management derivatives
Non-Interest Income
Investment fair value changes, net	(38)		0	(303)		0
Operating Segments | CoreVest | Risk management derivatives gains (losses), net
Non-Interest Income
Investment fair value changes, net	0		0	0		0
Operating Segments | Redwood Investments
Segment Reporting [Line Items]
Interest income	301,749		219,744	570,497		421,313
Interest expense	(291,579)		(202,280)	(547,885)		(387,325)
Net interest income (expense)	10,170		17,464	22,612		33,988
Non-Interest Income
Mortgage banking activities, net, excluding risk management derivatives	0		0	0		0
Risk management derivatives (losses) gains, net	0		0	0		0
Total Mortgage banking activities, net	0		0	0		0
Investment fair value changes, net	(10,171)		(8,998)	(25,614)		(5,375)
HEI income, net	493		126	1,068		181
Servicing income, net	2,618		1,608	10,639		5,015
Fee income (loss), net	453		412	645		554
Other income (loss), net	5,193		394	6,091		764
Realized gains, net	0		640	0		1,207
Total non-interest income (loss), net	(1,414)		(5,818)	(7,171)		2,346
General and administrative expenses	(853)		(1,528)	(4,237)		(2,877)
Portfolio management costs	(3,436)		(2,594)	(7,591)		(4,654)
Loan acquisition costs	0		0	0		0
Other expenses	(2,343)		(1,832)	(7,458)		(3,539)
Benefit from (Provision for) income taxes	(623)		1,567	(1,996)		1,871
Net (Loss) Income	1,501		7,259	(5,841)		27,135
Dividends on preferred stock	(758)		(500)	(1,416)		(1,051)
Net (Loss) Income (Related) Available To Common Stockholders	743		6,759	(7,257)		26,084
Total Assets	24,322,023		15,982,357	24,322,023		15,982,357
Operating Segments | Redwood Investments | Investment fair value changes, net, excluding risk management derivatives
Non-Interest Income
Investment fair value changes, net	26,153		(26,958)	48,968		(49,626)
Operating Segments | Redwood Investments | Risk management derivatives gains (losses), net
Non-Interest Income
Investment fair value changes, net	(36,324)		17,960	(74,582)		44,251
Operating Segments | Legacy Investments
Segment Reporting [Line Items]
Interest income	3,334		23,449	7,334		57,601
Interest expense	(13,737)		(38,879)	(26,447)		(77,731)
Net interest income (expense)	(10,403)		(15,430)	(19,113)		(20,130)
Non-Interest Income
Mortgage banking activities, net, excluding risk management derivatives	0		0	0		0
Risk management derivatives (losses) gains, net	0		0	0		0
Total Mortgage banking activities, net	0		0	0		0
Investment fair value changes, net	(12,314)		(75,574)	(19,805)		(84,305)
HEI income, net	2,305		(13,025)	8,839		(2,914)
Servicing income, net	0		0	0		0
Fee income (loss), net	11		(985)	(122)		(1,855)
Other income (loss), net	974		0	1,924		0
Realized gains, net	0		0	0		0
Total non-interest income (loss), net	(9,024)		(89,584)	(9,164)		(89,074)
General and administrative expenses	(15)		(57)	(31)		(73)
Portfolio management costs	(3,591)		(7,434)	(8,138)		(11,865)
Loan acquisition costs	0		0	0		0
Other expenses	(393)		0	(393)		0
Benefit from (Provision for) income taxes	328		2,535	938		2,535
Net (Loss) Income	(23,098)		(109,970)	(35,901)		(118,607)
Dividends on preferred stock	(222)		(645)	(479)		(1,354)
Net (Loss) Income (Related) Available To Common Stockholders	(23,320)		(110,615)	(36,380)		(119,961)
Total Assets	915,571		2,953,731	915,571		2,953,731
Operating Segments | Legacy Investments | Investment fair value changes, net, excluding risk management derivatives
Non-Interest Income
Investment fair value changes, net	(12,314)		(74,606)	(19,789)		(77,677)
Operating Segments | Legacy Investments | Risk management derivatives gains (losses), net
Non-Interest Income
Investment fair value changes, net	0		(968)	(16)		(6,628)
Corporate/ Other
Segment Reporting [Line Items]
Interest income	187		385	452		681
Interest expense	0		0	0		0
Net interest income (expense)	187		385	452		681
Non-Interest Income
Mortgage banking activities, net, excluding risk management derivatives	0		0	0		0
Risk management derivatives (losses) gains, net	0		0	0		0
Total Mortgage banking activities, net	0		0	0		0
Investment fair value changes, net	0		(132)	0		(212)
HEI income, net	0		0	0		0
Servicing income, net	0		0	0		0
Fee income (loss), net	0		0	0		0
Other income (loss), net	0		(757)	0		(1,259)
Realized gains, net	0		0	0		0
Total non-interest income (loss), net	0		(889)	0		(1,471)
General and administrative expenses	(20,691)		(17,975)	(44,146)		(37,138)
Portfolio management costs	(3)		0	(30)		0
Loan acquisition costs	0		0	0		0
Other expenses	0		0	0		0
Benefit from (Provision for) income taxes	150		347	452		394
Net (Loss) Income	(20,357)		(18,132)	(43,272)		(37,534)
Dividends on preferred stock	0		0	0		0
Net (Loss) Income (Related) Available To Common Stockholders	(20,357)		(18,132)	(43,272)		(37,534)
Total Assets	188,268		406,072	188,268		406,072
Corporate/ Other | Investment fair value changes, net, excluding risk management derivatives
Non-Interest Income
Investment fair value changes, net	0		(132)	0		(212)
Corporate/ Other | Risk management derivatives gains (losses), net
Non-Interest Income
Investment fair value changes, net	$ 0		$ 0	$ 0		$ 0

[1] Our consolidated balance sheets include assets of consolidated variable interest entities (“VIEs”) that can only be used to settle obligations of these VIEs and liabilities of consolidated VIEs for which creditors do not have recourse to Redwood Trust, Inc. or its affiliates. At June 30, 2026 and December 31, 2025, assets of consolidated VIEs totaled $24,372,361 and $18,927,094, respectively. At June 30, 2026 and December 31, 2025, liabilities of consolidated VIEs totaled $22,877,902 and $17,850,175, respectively. See Note 16 for further discussion.