Business Purpose Loans - Activity and Characteristics of Business Purpose Loans (Details) $ in Thousands	12 Months Ended
Dec. 31, 2022 USD ($) loan	Dec. 31, 2021 USD ($) loan	Dec. 31, 2020 USD ($)
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal balance of loans originated	$ 3,841,952	$ 13,188,434	$ 4,431,468
Principal payments on real estate securities	32,735	60,667	27,210
Transfers from loans held-for-sale to loans held-for-investment	2,949,262	5,026,723	1,868,656
Transfers from loans held-for-investment to loans held-for-sale	0	92,400	$ 64,520
Redwood \| Riverbend Acquisition
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal balance of loans acquired	$ 60,000
Single-family rental loans, held-for-sale
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	91
Unpaid principal balance	$ 389,846
Single-family rental loans, held-for-sale \| Redwood
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal balance of loans originated	1,000,109	1,254,913
Principal balance of loans acquired	100,349	68,804
Principal payments on real estate securities	429,873	193,963
Transfers from loans held-for-sale to loans held-for-investment	561,218	1,116,443
Transfers from loans held-for-investment to loans held-for-sale	0	92,455
Gain (loss) on investments	0	0
Single-family rental loans, held-for-sale \| Redwood \| Business Purpose Mortgage Banking Activities
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Gain (loss) on investments	(91,024)	63,206
Business purpose loans held-for-investment \| Redwood
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal balance of loans originated	1,698,227	894,908
Principal balance of loans acquired	97,787	65,315
Principal payments on real estate securities	79,608	9,484
Transfers from loans held-for-sale to loans held-for-investment	584,233	358,884
Transfers from loans held-for-investment to loans held-for-sale	0
Gain (loss) on investments	(5,805)	1,483
Business purpose loans held-for-investment \| Redwood \| Business Purpose Mortgage Banking Activities
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Gain (loss) on investments	$ 1,881	$ 7,188
Business purpose loans held-for-investment \| CAFL
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	1,875	1,640
Unpaid principal balance	$ 514,666	$ 274,617
Business Purpose Loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fee income	41,000
Fair value of loans	5,332,586	4,790,989
Business Purpose Loans Term Loans \| CAFL
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Gain (loss) on investments	(441,318)	(158,081)
Bridge Loans Held For Investment At Fair Value \| CAFL
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Gain (loss) on investments	$ (435)	$ (1,548)
Single family rental loans held for investment at fair value \| CAFL
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	1,131	1,173
Unpaid principal balance	$ 3,263,421	$ 3,340,949
Fair value of loans	$ 2,944,984	$ 3,488,074
Weighted average coupon rate (as a percent)	5.22%	5.17%
Weighted average remaining loan term (years)	6 years	6 years
Loans, at fair value	$ 13,686	$ 12,648
Number of loans in foreclosure \| loan	9	9
Single family rental loans held for investment at fair value \| CAFL \| Financing Receivables, Equal to Greater than 90 Days Past Due
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of loans with 90+ day delinquencies \| loan	16	18
Loans, at fair value	$ 37,072	$ 41,998
Single-Family Rental Loans, Held-For-Sale \| Redwood
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	91	245
Unpaid principal balance	$ 389,846	$ 348,232
Fair value of loans	$ 358,791	$ 358,309
Weighted average coupon rate (as a percent)	5.98%	4.73%
Weighted average remaining loan term (years)	10 years	12 years
Loans, at fair value	$ 536	$ 5,473
Number of loans in foreclosure \| loan	1	7
Loans held as assets amount in foreclosure	$ 536	$ 4,305
Single-Family Rental Loans, Held-For-Sale \| Redwood \| Financing Receivables, Equal to Greater than 90 Days Past Due
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans	$ 536	$ 4,238
Number of loans with 90+ day delinquencies \| loan	1	6
Loans, at fair value	$ 536	$ 5,384
Single-Family Rental Loans, Held-For-Sale \| Redwood \| Loans Pledged As Collateral, Short Term Debt
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Gain (loss) on investments	291,406	75,873
Single-Family Rental Loans, Held-For-Sale \| Redwood \| Loans Pledged As Collateral, Long Term debt
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Gain (loss) on investments	$ 66,567	$ 244,703
Business Purpose Bridge Loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	1,601	1,134
Unpaid principal balance	$ 1,518,427	$ 670,392
Fair value of loans	$ 1,512,428	$ 666,364
Weighted average coupon rate (as a percent)	9.61%	6.91%
Weighted average remaining loan term (years)	2 years	1 year
Loans, at fair value	$ 34,039	$ 18,043
Number of loans in foreclosure \| loan	48	28
Loans held as assets amount in foreclosure	$ 29,438	$ 14,257
Business Purpose Bridge Loans \| Financing Receivables, Equal to Greater than 90 Days Past Due
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans	$ 29,663	$ 14,218
Number of loans with 90+ day delinquencies \| loan	49	31
Loans, at fair value	$ 34,264	$ 18,032
Business Purpose Bridge Loans \| Loans Pledged As Collateral, Short Term Debt
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Gain (loss) on investments	579,666	91,814
Business Purpose Bridge Loans \| Loans Pledged As Collateral, Long Term debt
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Gain (loss) on investments	$ 897,782	$ 554,597
Business Purpose Bridge Loans \| CAFL
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of Loans \| loan	1,875	1,640
Unpaid principal balance	$ 514,666	$ 274,617
Fair value of loans	$ 516,383	$ 278,242
Weighted average coupon rate (as a percent)	9.67%	7.05%
Weighted average remaining loan term (years)	1 year	1 year
Loans, at fair value	$ 7,328	$ 0
Number of loans in foreclosure \| loan	48	0
Loans held as assets amount in foreclosure	$ 7,438	$ 0
Business Purpose Bridge Loans \| CAFL \| Financing Receivables, Equal to Greater than 90 Days Past Due
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Fair value of loans	$ 7,438	$ 0
Number of loans with 90+ day delinquencies \| loan	48	0
Loans, at fair value	$ 7,328	$ 0

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Financing Receivable, Contract Maturities

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Principal Balance of Loans Acquired During Period

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The cash inflow from repayments of the balance excluding interest (principal) on real estate securities.

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Number of mortgage loans within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

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This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected.

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Amount of realized and unrealized gain (loss) on investment.

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Amortized cost, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease.

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The aggregate cash outflow used to purchase all loans that are held with the intention to resell in the near future.

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