Short-Term Debt - Outstanding Balances of Short-Term Debt by Type of Collateral Securing Debt (Details)		12 Months Ended
		Dec. 31, 2022 USD ($) facility	Dec. 31, 2021 USD ($) facility
Short-term Debt [Line Items]
Outstanding Balance	[1]	$ 2,029,679,000	$ 2,177,362,000
Line of Credit
Short-term Debt [Line Items]
Number of Facilities | facility		19	13
Outstanding Balance		$ 1,620,096,000	$ 1,882,915,000
Line of Credit | Residential loan warehouse
Short-term Debt [Line Items]
Number of Facilities | facility		7	7
Outstanding Balance		$ 703,406,000	$ 1,669,344,000
Limit		$ 2,550,000,000	$ 2,900,000,000
Weighted Average Interest Rate		6.16%	1.87%
Weighted Average Days Until Maturity		267 days	153 days
Line of Credit | Business purpose loan warehouse
Short-term Debt [Line Items]
Number of Facilities | facility		4	2
Outstanding Balance		$ 680,100,000	$ 138,746,000
Limit		$ 1,650,000,000	$ 350,000,000
Weighted Average Interest Rate		6.93%	3.34%
Weighted Average Days Until Maturity		179 days	105 days
Line of Credit | Real estate securities repo
Short-term Debt [Line Items]
Number of Facilities | facility		7	4
Outstanding Balance		$ 124,909,000	$ 74,825,000
Limit		$ 0	$ 0
Weighted Average Interest Rate		5.22%	1.13%
Weighted Average Days Until Maturity		27 days	33 days
Line of Credit | HEI warehouse
Short-term Debt [Line Items]
Number of Facilities | facility		1
Outstanding Balance		$ 111,681,000
Limit		$ 150,000,000
Weighted Average Interest Rate		8.54%
Weighted Average Days Until Maturity		306 days
Servicer advance financing
Short-term Debt [Line Items]
Number of Facilities | facility		1	1
Outstanding Balance		$ 206,510,000	$ 294,447,000
Limit		$ 290,000,000	$ 350,000,000
Weighted Average Interest Rate		6.67%	1.90%
Weighted Average Days Until Maturity		305 days	306 days
Promissory notes
Short-term Debt [Line Items]
Outstanding Balance		$ 27,058,000
Weighted Average Interest Rate		6.64%
Convertible notes, net
Short-term Debt [Line Items]
Outstanding Balance		$ 176,015,000	$ 0
Weighted Average Interest Rate		4.75%
Weighted Average Days Until Maturity		227 days

[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.