Residential Consumer Loans - Characteristics of Residential Consumer Loans Held-for-Investment (Details) - Held-for-investment at fair value $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2024 USD ($) loan	Dec. 31, 2023 USD ($) loan
Legacy Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan	1,017	1,059
Unpaid principal balance	$ 146,688	$ 156,053
Fair value of loans	$ 131,859	$ 139,739
Weighted average coupon	6.59%	6.54%
Number of loans in foreclosure \| loan	5	7
Unpaid principal balance of loans in foreclosure	$ 1,086	$ 1,848
Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan	7,078	6,070
Unpaid principal balance	$ 6,294,974	$ 5,242,860
Fair value of loans	$ 5,640,341	$ 4,640,464
Weighted average coupon	4.52%	4.08%
Number of loans in foreclosure \| loan	6	5
Unpaid principal balance of loans in foreclosure	$ 5,335	$ 3,386
Freddie Mac SLST
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of loans \| loan	10,187	10,302
Unpaid principal balance	$ 1,593,040	$ 1,614,974
Fair value of loans	$ 1,332,686	$ 1,359,242
Weighted average coupon	4.50%	4.50%
Number of loans in foreclosure \| loan	286	292
Unpaid principal balance of loans in foreclosure	$ 47,490	$ 47,654
Financing Receivables, Equal to Greater than 90 Days Past Due \| Legacy Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of loans with 90+ day delinquencies \| loan	15	16
Fair value of loans with 90+ day delinquencies	$ 4,328	$ 4,141
Financing Receivables, Equal to Greater than 90 Days Past Due \| Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of loans with 90+ day delinquencies \| loan	14	11
Fair value of loans with 90+ day delinquencies	$ 11,904	$ 8,882
Financing Receivables, Equal to Greater than 90 Days Past Due \| Freddie Mac SLST
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Number of loans with 90+ day delinquencies \| loan	743	796
Fair value of loans with 90+ day delinquencies	$ 125,401	$ 132,307

Fair Value, Option, Loans Held As Assets, Aggregate Amount In Foreclosure

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Financing Receivable, Number Of Loans In Foreclosure

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Financing Receivable, Number Of Loans Past Due

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Loans Held-for-Investment, Weighted Average Coupon Rate

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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-Name Regulation S-X (SX)
-Number 210
-Section 12
-Subsection 29
-Publisher SEC

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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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Subsection 29
-Footnote 3
-Publisher SEC

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 310
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-Publisher FASB
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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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-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (e)(1)
-Publisher FASB
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- Definition

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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(5)(b))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1

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This is the sum of principal amount outstanding for both securitized and unsecuritized loans of all types.

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