Segment Information - Schedule of Business Segment Financial Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025		Dec. 31, 2024		Dec. 31, 2023
Segment Reporting Information [Line Items]
Interest income	$ 1,182,926		$ 945,164		$ 724,462
Interest expense	(1,100,229)		(842,556)		(631,519)
Net interest income	82,697		102,608		92,943
Non-interest income (loss)
Mortgage banking activities, net, excluding risk management derivatives	102,625		118,903		86,208
Risk management derivatives (losses) gains, net	64,481		(19,505)		(18,822)
Total Mortgage banking activities, net	167,106		99,398		67,386
Investment fair value changes, net	(97,369)		(14,759)		(44,400)
HEI income (loss), net	711		42,085		35,241
Servicing income, net	9,993		14,414		7,033
Fee income (loss), net	10,957		11,030		8,213
Other income (loss), net	3,883		1,830		(2,484)
Realized gains, net	(608)		306		1,699
Total non-interest income, net	94,673		154,304		72,688
General and administrative expenses	(153,946)		(136,393)		(128,295)
Portfolio management costs	(28,258)		(20,915)		(14,571)
Loan acquisition costs	(18,143)		(12,675)		(7,166)
Other expenses	(21,864)		(14,088)		(16,238)
(Provision for) benefit from income taxes	(25,185)		(18,837)		(1,635)
Net (loss) income	(70,026)		54,004		(2,274)
Total Assets	23,701,114	[1]	18,258,344	[1]	14,504,327
Investment fair value changes, net, excluding risk management derivatives
Non-interest income (loss)
Investment fair value changes, net	(138,953)		(4,570)		(42,921)
Risk management derivatives gains (losses), net
Non-interest income (loss)
Investment fair value changes, net	41,584		(10,189)		(1,479)
CoreVest Mortgage Banking
Non-interest income (loss)
Total Mortgage banking activities, net	51,000		42,000
Operating Segments | Sequoia Mortgage Banking
Segment Reporting Information [Line Items]
Interest income	183,581		97,860		25,404
Interest expense	(101,174)		(54,065)		(24,114)
Net interest income	82,407		43,795		1,290
Non-interest income (loss)
Mortgage banking activities, net, excluding risk management derivatives	49,429		82,202		45,690
Risk management derivatives (losses) gains, net	66,220		(24,623)		(17,908)
Total Mortgage banking activities, net	115,649		57,579		27,782
Investment fair value changes, net	0		0		1,076
HEI income (loss), net	0		0		0
Servicing income, net	0		0		0
Fee income (loss), net	0		0		0
Other income (loss), net	0		0		0
Realized gains, net	0		0		0
Total non-interest income, net	115,649		57,579		28,858
General and administrative expenses	(34,019)		(20,008)		(17,171)
Portfolio management costs	0		0		0
Loan acquisition costs	(7,506)		(3,860)		(1,266)
Other expenses	0		0		0
(Provision for) benefit from income taxes	(30,418)		(16,009)		(1,659)
Net (loss) income	126,113		61,497		10,052
Total Assets	3,321,116		1,231,723		971,535
Operating Segments | Sequoia Mortgage Banking | Investment fair value changes, net, excluding risk management derivatives
Non-interest income (loss)
Investment fair value changes, net	0		0		1,076
Operating Segments | Sequoia Mortgage Banking | Risk management derivatives gains (losses), net
Non-interest income (loss)
Investment fair value changes, net	0		0		0
Operating Segments | CoreVest Mortgage Banking
Segment Reporting Information [Line Items]
Interest income	18,468		20,280		15,896
Interest expense	(10,070)		(14,970)		(13,078)
Net interest income	8,398		5,310		2,818
Non-interest income (loss)
Mortgage banking activities, net, excluding risk management derivatives	53,196		36,701		40,518
Risk management derivatives (losses) gains, net	(1,739)		5,118		(914)
Total Mortgage banking activities, net	51,457		41,819		39,604
Investment fair value changes, net	0		0		0
HEI income (loss), net	0		0		0
Servicing income, net	0		0		0
Fee income (loss), net	12,834		10,930		5,593
Other income (loss), net	3,342		0		20
Realized gains, net	0		0		0
Total non-interest income, net	67,633		52,749		45,217
General and administrative expenses	(40,242)		(40,008)		(44,547)
Portfolio management costs	0		0		0
Loan acquisition costs	(10,481)		(8,563)		(5,900)
Other expenses	(8,426)		(9,413)		(12,442)
(Provision for) benefit from income taxes	3,235		2,219		2,279
Net (loss) income	20,117		2,294		(12,575)
Total Assets	357,988		317,612		293,225
Operating Segments | CoreVest Mortgage Banking | Investment fair value changes, net, excluding risk management derivatives
Non-interest income (loss)
Investment fair value changes, net	0		0		0
Operating Segments | CoreVest Mortgage Banking | Risk management derivatives gains (losses), net
Non-interest income (loss)
Investment fair value changes, net	0		0		0
Operating Segments | Redwood Investments
Segment Reporting Information [Line Items]
Interest income	895,416		661,489		465,134
Interest expense	(814,035)		(562,148)		(379,710)
Net interest income	81,381		99,341		85,424
Non-interest income (loss)
Mortgage banking activities, net, excluding risk management derivatives	0		0		0
Risk management derivatives (losses) gains, net	0		0		0
Total Mortgage banking activities, net	0		0		0
Investment fair value changes, net	923		38,497		23,695
HEI income (loss), net	1,419		61		23,569
Servicing income, net	9,993		14,414		7,033
Fee income (loss), net	1,022		965		1,041
Other income (loss), net	1,550		3,122		716
Realized gains, net	1,207		565		1,502
Total non-interest income, net	16,114		57,624		57,556
General and administrative expenses	(5,549)		(7,654)		(7,283)
Portfolio management costs	(10,930)		(5,836)		(6,039)
Loan acquisition costs	0		(14)		0
Other expenses	(12,938)		(4,675)		(5,796)
(Provision for) benefit from income taxes	7		(5,586)		(2,946)
Net (loss) income	68,085		133,200		120,916
Total Assets	18,744,747		13,277,770		9,450,031
Operating Segments | Redwood Investments | Investment fair value changes, net, excluding risk management derivatives
Non-interest income (loss)
Investment fair value changes, net	(49,124)		60,068		24,579
Operating Segments | Redwood Investments | Risk management derivatives gains (losses), net
Non-interest income (loss)
Investment fair value changes, net	50,047		(21,571)		(884)
Operating Segments | Legacy Investments
Segment Reporting Information [Line Items]
Interest income	83,734		162,450		210,344
Interest expense	(108,762)		(140,357)		(156,817)
Net interest income	(25,028)		22,093		53,527
Non-interest income (loss)
Mortgage banking activities, net, excluding risk management derivatives	0		0		0
Risk management derivatives (losses) gains, net	0
Total Mortgage banking activities, net	0		0		0
Investment fair value changes, net	(99,171)		(51,577)		(66,177)
HEI income (loss), net	(708)		42,024		11,672
Servicing income, net	0		0		0
Fee income (loss), net	(2,899)		(1,020)		1,447
Other income (loss), net	(1,091)		0		0
Realized gains, net	(1,767)		0		(644)
Total non-interest income, net	(105,636)		(10,573)		(53,702)
General and administrative expenses	(111)		(68)		(525)
Portfolio management costs	(17,279)		(15,021)		(8,492)
Loan acquisition costs	(156)		(238)		0
Other expenses	(500)		0		0
(Provision for) benefit from income taxes	1,769		0		0
Net (loss) income	(146,941)		(3,807)		(9,192)
Total Assets	942,465		3,101,377		3,408,949
Operating Segments | Legacy Investments | Investment fair value changes, net, excluding risk management derivatives
Non-interest income (loss)
Investment fair value changes, net	(90,708)		(62,959)		(65,582)
Operating Segments | Legacy Investments | Risk management derivatives gains (losses), net
Non-interest income (loss)
Risk management derivatives (losses) gains, net			0		0
Investment fair value changes, net	(8,463)		11,382		(595)
Corporate/ Other
Segment Reporting Information [Line Items]
Interest income	1,727		3,085		7,684
Interest expense	(66,188)		(71,016)		(57,800)
Net interest income	(64,461)		(67,931)		(50,116)
Non-interest income (loss)
Mortgage banking activities, net, excluding risk management derivatives	0		0		0
Risk management derivatives (losses) gains, net	0		0		0
Total Mortgage banking activities, net	0		0		0
Investment fair value changes, net	879		(1,679)		(2,994)
HEI income (loss), net	0		0		0
Servicing income, net	0		0		0
Fee income (loss), net	0		155		132
Other income (loss), net	82		(1,292)		(3,220)
Realized gains, net	(48)		(259)		841
Total non-interest income, net	913		(3,075)		(5,241)
General and administrative expenses	(74,025)		(68,655)		(58,769)
Portfolio management costs	(49)		(58)		(40)
Loan acquisition costs	0		0		0
Other expenses	0		0		2,000
(Provision for) benefit from income taxes	222		539		691
Net (loss) income	(137,400)		(139,180)		(111,475)
Total Assets	334,798		329,862		380,587
Corporate/ Other | Investment fair value changes, net, excluding risk management derivatives
Non-interest income (loss)
Investment fair value changes, net	879		(1,679)		(2,994)
Corporate/ Other | Risk management derivatives gains (losses), net
Non-interest income (loss)
Investment fair value changes, net	$ 0		$ 0		$ 0

[1] Our consolidated balance sheets include assets of 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 December 31, 2025 and 2024, assets of consolidated VIEs totaled $18,927,094 and $14,654,942, respectively. At December 31, 2025 and 2024, liabilities of consolidated VIEs totaled $17,850,175 and $13,620,239, respectively. See Note 15 for further discussion.