Asset-Backed Securities Issued - Additional Information (Details) - USD ($)		3 Months Ended	12 Months Ended
		Sep. 30, 2020	Dec. 31, 2022	Dec. 31, 2052	May 29, 2029	Mar. 31, 2029	Jul. 31, 2023	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Debt Instrument [Line Items]
Other assets	[1]		$ 211,240,000						$ 231,117,000
Variable Interest Entity, Primary Beneficiary
Debt Instrument [Line Items]
VIE, ownership interest rate (as a percent)			80.00%
Variable Interest Entity, Primary Beneficiary | HEI
Debt Instrument [Line Items]
ABS issued, at amortized cost										$ 146,000,000
CoreVest | Variable Interest Entity, Primary Beneficiary
Debt Instrument [Line Items]
ABS issued, at amortized cost								$ 215,000,000		$ 270,000,000
Freddie Mac SLST | Variable Interest Entity, Primary Beneficiary
Debt Instrument [Line Items]
ABS issued, at amortized cost		$ 210,000,000
2022 Asset Backed Securities Sold | CoreVest
Debt Instrument [Line Items]
Debt instrument, face amount			$ 215,000,000
Bridge loan			232,000,000
Restricted cash			18,000,000
2022 Asset Backed Securities Sold | CoreVest | Variable Interest Entity, Primary Beneficiary
Debt Instrument [Line Items]
Debt instrument, face amount			209,000,000
Debt discount			6,000,000
Asset-backed Securities | Variable Interest Entity, Primary Beneficiary
Debt Instrument [Line Items]
Debt instrument, face amount			85,000,000
Debt discount			$ 1,000,000
Debt instrument, interest rate (as a percent)			4.75%
VIE, ownership interest rate (as a percent)		100.00%
Asset-backed Securities | Variable Interest Entity, Primary Beneficiary | Forecast
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)				2.00%		2.00%	7.75%
Asset-backed Securities | CoreVest
Debt Instrument [Line Items]
Debt instrument, face amount			$ 485,000,000						270,000,000
Bridge loan			284,000,000
Restricted cash			16,000,000
Securitized asset backed securities, borrowing capacity			250,000,000
Other assets			11,000,000
Asset-backed Securities | CoreVest | Variable Interest Entity, Primary Beneficiary
Debt Instrument [Line Items]
Debt instrument, face amount			269,000,000
Debt discount			$ 1,000,000
Debt instrument, interest rate (as a percent)			4.32%
Asset-backed Securities | Freddie Mac SLST
Debt Instrument [Line Items]
Debt instrument, face amount			$ 86,000,000						$ 145,000,000
2021 Asset Backed Securities Sold | Variable Interest Entity, Primary Beneficiary | Forecast
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)					2.00%
2021 Asset Backed Securities Sold | CoreVest
Debt Instrument [Line Items]
Debt instrument, face amount			270,000,000
Securitized asset backed securities, borrowing capacity			$ 300,000,000
2021 Asset Backed Securities Sold | CoreVest | Variable Interest Entity, Primary Beneficiary
Debt Instrument [Line Items]
Debt instrument, interest rate (as a percent)			2.34%
Contractual maturities of over five years | Asset-backed Securities
Debt Instrument [Line Items]
Contractual maturities of ABS (in years)			5 years

[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 December 31, 2022 and 2021, assets of consolidated VIEs totaled $9,257,291 and $10,661,081, respectively. At December 31, 2022 and 2021, liabilities of consolidated VIEs totaled $8,270,276 and $9,619,347, respectively. See Note 4 for further discussion.