Commitments and Contingencies - Additional Information (Details) $ in Thousands		3 Months Ended			12 Months Ended
		Mar. 31, 2022 USD ($) repurchase_request lease loan	Sep. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($) commitment	Dec. 31, 2018 partnership	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Loss Contingencies [Line Items]
Lessee, number of leases | lease		7
Present value of remaining lease payments		$ 23,442
Operating lease expense		1,000		$ 1,000
Operating lease liabilities		$ 20,218			$ 20,960
Operating lease liability, statement of financial position [Extensible List]		Accounts Payable and Accrued Liabilities
Operating lease right-of-use assets		$ 17,917			18,772
Operating lease right-of-use asset, statement of financial position [Extensible List]		Other assets
Weighted average remaining lease term		6 years
Discount rate (as a percent)		5.10%
Derivative liabilities	[1]	$ 80,260			3,317
Net market valuation gains (losses)		(200)		1,000
Number of partnerships, committed to fund | partnership						2
Other income related to risk sharing agreement		460		882
Guarantee obligations		7,046			7,459
Guarantee obligations, credit reserve		5,000
Special purpose entities assets		34,000
Special purpose entities liabilities		7,000
Residential repurchase reserve		$ 9,529			9,306
Number of residential repurchase requests (in repurchase requests) | repurchase_request		0
Number of loans repurchased | loan		0
Residential loans repurchase provision (reversal)		$ 200		(100)
Aggregate amount of loss contingency reserves		2,000
Maximum
Loss Contingencies [Line Items]
Loss from arrangements		100
Residential Loans
Loss Contingencies [Line Items]
Loan principal		1,369,366			1,813,865
Fair value of loans		1,347,069			1,845,282
Financing Receivables, Equal to Greater than 90 Days Past Due | Residential Loans
Loss Contingencies [Line Items]
Fair value of loans		616			2,923
Other income
Loss Contingencies [Line Items]
Other income related to risk sharing agreement		500		1,000
Mortgage banking and investment activities
Loss Contingencies [Line Items]
Market valuation gains (losses) related to these investments		100		$ (100)
Guarantee Obligations
Loss Contingencies [Line Items]
Original unpaid balance of loans subject to risk sharing agreements							$ 3,190,000	$ 3,190,000
Potential future payments on loans		44,000
Loan principal		$ 504,000
Weighted average original FICO score		756
Weighted average original loan-to-value (LTV)		74.00%
Guarantee Obligations | Residential Loans
Loss Contingencies [Line Items]
Unpaid principal balance of loans in foreclosure		$ 200
Guarantee Obligations | Financing Receivables, Equal to Greater than 90 Days Past Due
Loss Contingencies [Line Items]
Fair value of loans		14,000
Commitment To Fund Residential Bridge Loan
Loss Contingencies [Line Items]
Other commitments made		792,000
Derivative liabilities		(1,000)
Commitment To Acquire HEIs
Loss Contingencies [Line Items]
Other commitments made		70,000
Payments for other commitments		125,000	$ 125,000
Total commitment amount		250,000
Commitment To Fund Strategic Investment
Loss Contingencies [Line Items]
Other commitments made		300
Payments for other commitments		25,000
Commitment To Fund RWT Horizons Investments
Loss Contingencies [Line Items]
Other commitments made		$ 4,000
Payments for other commitments					$ 5,000
Number of commitments | commitment					2

[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, 2022 and December 31, 2021, assets of consolidated VIEs totaled $10,250,802 and $10,661,081, respectively. At March 31, 2022 and December 31, 2021, liabilities of consolidated VIEs totaled $9,202,156 and $9,619,347, respectively. See Note 4 for further discussion.