Commitments and Contingencies - Additional Information (Details)			3 Months Ended		12 Months Ended
		Jul. 01, 2022 USD ($)	Mar. 31, 2023 USD ($) lease loan repurchase_request tranche	Mar. 31, 2022 USD ($) repurchase_request loan	Dec. 31, 2021 USD ($)	Dec. 31, 2018 partnership	Dec. 31, 2022 USD ($) loan	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Loss Contingencies [Line Items]
Lessee, number of leases | lease			10
Present value of remaining lease payments			$ 19,981,000
Operating lease expense			$ 1,000,000	$ 1,000,000
Lessee, number of office leases | lease			1
Operating lease liabilities			$ 17,638,000				$ 18,563,000
Operating lease liability, statement of financial position [Extensible List]			Accounts Payable and Accrued Liabilities
Operating lease right-of-use assets			$ 15,297,000				16,177,000
Operating lease right-of-use asset, statement of financial position [Extensible List]			Other assets
Weighted average remaining lease term			5 years
Discount rate (as a percent)			5.20%
Derivative liabilities	[1]		$ 10,736,000				16,855,000
Market valuation adjustments			11,270,000	$ (1,859,000)
Number of partnerships, committed to fund | partnership						2
Guarantee obligations			6,223,000				6,344,000
Guarantee obligations, credit reserve			5,000,000
Special purpose entities assets			30,000,000				30,000,000
Special purpose entities liabilities			6,000,000				6,000,000
Residential repurchase reserve			5,858,000				7,051,000
Aggregate amount of loss contingency reserves			2,000,000
Riverbend Funding, LLC
Loss Contingencies [Line Items]
Earnout period		2 years
Potential future payments on loans		$ 25,300,000
Contingent consideration			0
Maximum
Loss Contingencies [Line Items]
Loss from arrangements			100,000
Residential Loans
Loss Contingencies [Line Items]
Unpaid principal balance			27,935,000				822,063,000
Fair value of loans			$ 26,975,000				$ 780,781,000
Number of loans in foreclosure | loan			0				0
Business Purpose Loans
Loss Contingencies [Line Items]
Residential repurchase reserve			$ 0				$ 1,000,000
Number of residential repurchase requests (in repurchase requests) | repurchase_request			4	0
Number of loans repurchased | loan			11	0
Repurchase request outstanding			$ 0				1,000,000
Other income
Loss Contingencies [Line Items]
Other income related to risk sharing agreement			200,000
Guarantee Obligations
Loss Contingencies [Line Items]
Potential future payments on loans			44,000,000
Original unpaid balance of loans subject to risk sharing agreements								$ 3,190,000,000	$ 3,190,000,000
Unpaid principal balance			$ 429,000,000
Weighted average original FICO score			759
Weighted average original loan-to-value (LTV)			74.00%
Guarantee Obligations | Residential Loans
Loss Contingencies [Line Items]
Number of loans in foreclosure | tranche			5
Unpaid principal balance of loans in foreclosure			$ 1,000,000
Guarantee Obligations | Financing Receivables, Equal to Greater than 90 Days Past Due
Loss Contingencies [Line Items]
Fair value of loans			9,000,000
Repurchase Reserves
Loss Contingencies [Line Items]
Residential repurchase reserve			$ 6,000,000				$ 6,000,000
Number of residential repurchase requests (in repurchase requests) | repurchase_request			1	0
Number of loans repurchased | loan			5	0
Residential loans repurchase (reversal) provision			$ 0	$ (200,000)
Commitment To Fund Residential Bridge Loan
Loss Contingencies [Line Items]
Other commitments made			811,000,000
Derivative liabilities			(1,000,000)
Market valuation adjustments			400,000
Commitment To Acquire HEIs
Loss Contingencies [Line Items]
Cumulative commitment			8,000,000
Commitment To Fund Strategic Investment
Loss Contingencies [Line Items]
Other commitments made			15,000,000
Payments for other commitments				$ 25,000,000
Commitment To Fund RWT Horizons Investments
Loss Contingencies [Line Items]
Other commitments made			$ 1,000,000
Payments for other commitments					$ 5,000,000

[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.