Fair Value of Financial Instruments - Carrying Values and Estimated Fair Values of Assets and Liabilities (Details) - USD ($) $ in Thousands		Mar. 31, 2023	Dec. 31, 2022
Assets
Real estate securities, at fair value		$ 108,366	$ 108,329
HEIs	[1]	416,783	403,462
Derivative assets	[1]	11,497	20,830
Liabilities
Derivative liabilities	[1]	10,736	16,855
ABS issued, net, At fair value		7,968,135	7,424,132
Residential loans, held-for-sale, at fair value
Assets
Loans receivable, fair value		26,282	775,545
Servicer advance investments
Assets
MSRs		260,378	269,259
Carrying Value
Assets
Real estate securities, at fair value		243,346	240,475
Other financial instruments		5,727	6,155
Cash and cash equivalents		404,449	258,894
Restricted cash		86,037	70,470
Derivative assets		11,497	20,830
Margin receivable		17,079	13,802
Liabilities
Margin payable		2,558	5,944
Guarantee obligation		6,223	6,344
Derivative liabilities		10,736	16,855
ABS issued, net, At fair value		7,968,135	7,424,132
ABS issued, net, At amortized cost		478,984	562,620
Other long-term debt, net		1,076,099	1,077,200
Convertible notes, net		661,634	693,473
Trust preferred securities and subordinated notes, net		138,779	138,767
Carrying Value | Servicer Advance Investments
Assets
MSRs		260,378	269,259
Carrying Value | MSRs
Assets
MSRs		24,831	25,421
Carrying Value | Excess MSRs
Assets
REO		38,807	39,035
Carrying Value | REO
Assets
REO		13,095	6,455
Carrying Value | Short-term debt
Liabilities
Short-term debt		1,472,968	1,853,664
Carrying Value | Servicer advance investments | Residential loans, held-for-sale, at fair value
Assets
Loans, held-for-sale		26,975	780,781
Carrying Value | Servicer advance investments | Residential loans, held-for-investment, at fair value
Assets
Loans receivable, fair value		5,465,883	4,832,407
Carrying Value | Servicer advance investments | Business purpose loans, held-for-sale, at fair value
Assets
Loans, held-for-sale		371,385	364,073
Carrying Value | Servicer advance investments | Business purpose loans, held-for-investment, at fair value
Assets
Loans receivable, fair value		4,993,264	4,968,513
Carrying Value | Servicer advance investments | Consolidated Agency multifamily loans, at fair value
Assets
Loans receivable, fair value		426,599	424,551
Fair Value
Assets
Real estate securities, at fair value		243,346	240,475
Other financial instruments		5,727	6,155
Cash and cash equivalents		404,449	258,894
Restricted cash		86,037	70,470
Derivative assets		11,497	20,830
Margin receivable		17,079	13,802
Liabilities
Margin payable		2,558	5,944
Guarantee obligation		4,612	4,738
Derivative liabilities		10,736	16,855
ABS issued, net, At fair value		7,968,135	7,424,132
ABS issued, net, At amortized cost		452,263	524,768
Other long-term debt, net		1,022,015	1,069,946
Convertible notes, net		620,465	638,049
Trust preferred securities and subordinated notes, net		87,885	83,700
Fair Value | Servicer Advance Investments
Assets
MSRs		260,378	269,259
Fair Value | MSRs
Assets
MSRs		24,831	25,421
Fair Value | Excess MSRs
Assets
REO		38,807	39,035
Fair Value | REO
Assets
REO		3,378	4,185
Fair Value | Short-term debt
Liabilities
Short-term debt		1,472,968	1,853,664
Fair Value | Servicer advance investments | Residential loans, held-for-sale, at fair value
Assets
Loans, held-for-sale		26,975	780,781
Fair Value | Servicer advance investments | Residential loans, held-for-investment, at fair value
Assets
Loans receivable, fair value		5,465,883	4,832,407
Fair Value | Servicer advance investments | Business purpose loans, held-for-sale, at fair value
Assets
Loans, held-for-sale		371,385	364,073
Fair Value | Servicer advance investments | Business purpose loans, held-for-investment, at fair value
Assets
Loans receivable, fair value		4,993,264	4,968,513
Fair Value | Servicer advance investments | Consolidated Agency multifamily loans, at fair value
Assets
Loans receivable, fair value		426,599	424,551
HEIs | Carrying Value
Assets
HEIs		416,783	403,462
Liabilities
HEI securitization non-controlling interest		23,097	22,329
HEIs | Fair Value
Assets
HEIs		416,783	403,462
Liabilities
HEI securitization non-controlling interest		$ 23,097	$ 22,329

[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 March 31, 2023 and December 31, 2022, assets of consolidated VIEs totaled $9,836,956 and $9,257,291, respectively. At March 31, 2023 and December 31, 2022, liabilities of consolidated VIEs totaled $8,729,585 and $8,270,276, respectively. See Note 4 for further discussion.