Residential Loans - Summary of Classifications and Carrying Value of Residential Loans (Details) - USD ($) $ in Thousands		Sep. 30, 2021	Dec. 31, 2020
Held-for-sale at fair value
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans	[1]	$ 1,495,079	$ 176,641
Held-for-investment at fair value | Legacy Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		242,234	285,935
Held-for-investment at fair value | Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		2,479,750	1,565,322
Held-for-investment at fair value | Freddie Mac SLST
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		1,999,405	2,221,153
Residential Loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		6,216,468	4,249,051
Residential Loans | Legacy Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		242,234	285,935
Residential Loans | Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		2,479,750	1,565,322
Residential Loans | Freddie Mac SLST
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		1,999,405	2,221,153
Residential Loans | Held-for-sale at fair value
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		1,495,079	176,641
Residential Loans | Held-for-sale at fair value | Legacy Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		0	0
Residential Loans | Held-for-sale at fair value | Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		0	0
Residential Loans | Held-for-sale at fair value | Freddie Mac SLST
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		0	0
Residential Loans | Held-for-investment at fair value
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		4,721,389	4,072,410
Residential Loans | Held-for-investment at fair value | Legacy Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		242,234	285,935
Residential Loans | Held-for-investment at fair value | Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		2,479,750	1,565,322
Residential Loans | Held-for-investment at fair value | Freddie Mac SLST
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		1,999,405	2,221,153
Residential Loans | Redwood
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		1,495,079	176,641
Residential Loans | Redwood | Held-for-sale at fair value
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		1,495,079	176,641
Residential Loans | Redwood | Held-for-investment at fair value
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans		$ 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 September 30, 2021 and December 31, 2020, assets of consolidated VIEs totaled $9,358,317 and $8,141,069, respectively. At September 30, 2021 and December 31, 2020, liabilities of consolidated VIEs totaled $8,391,761 and $7,348,713, respectively. See Note 4 for further discussion.