Asset-Backed Securities Issued - Schedule of Asset-Backed Securities Issued (Details)	Dec. 31, 2023 USD ($) series trust	Dec. 31, 2022 USD ($) series trust
Net investments in consolidated CAFL Term entities
Debt Instrument [Line Items]
Number of bridge securitization trusts \| trust	2	2
Asset-backed securities issued
Debt Instrument [Line Items]
ABS Issued, Net	$ 9,811,880,000	$ 7,986,752,000
Asset-backed securities issued \| Revision of Prior Period, Accounting Standards Update, Adjustment
Debt Instrument [Line Items]
ABS Issued, Net	(943,370,000)	(1,155,151,000)
Asset-backed securities issued \| Deferred Debt Issuance Costs
Debt Instrument [Line Items]
Unamortized debt discount and deferred debt issuance costs	(5,929,000)	(8,134,000)
Asset-backed securities issued \| Certificates with principal balance
Debt Instrument [Line Items]
ABS Issued, Net	10,588,659,000	8,944,351,000
Asset-backed securities issued \| Interest-only certificates at fair value
Debt Instrument [Line Items]
ABS Issued, Net	172,520,000	205,686,000
Asset-backed securities issued \| Legacy Sequoia
Debt Instrument [Line Items]
ABS Issued, Net	$ 138,530,000	$ 184,191,000
Number of Series \| series	20	20
Asset-backed securities issued \| Legacy Sequoia \| Revision of Prior Period, Accounting Standards Update, Adjustment
Debt Instrument [Line Items]
ABS Issued, Net	$ (12,738,000)	$ (16,036,000)
Asset-backed securities issued \| Legacy Sequoia \| Deferred Debt Issuance Costs
Debt Instrument [Line Items]
Unamortized debt discount and deferred debt issuance costs	$ 0	$ 0
Asset-backed securities issued \| Legacy Sequoia \| Minimum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	3.59%	2.69%
Asset-backed securities issued \| Legacy Sequoia \| Maximum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	6.66%	5.19%
Asset-backed securities issued \| Legacy Sequoia \| Certificates with principal balance
Debt Instrument [Line Items]
ABS Issued, Net	$ 151,106,000	$ 200,047,000
Asset-backed securities issued \| Legacy Sequoia \| Interest-only certificates at fair value
Debt Instrument [Line Items]
ABS Issued, Net	162,000	180,000
Asset-backed securities issued \| Sequoia
Debt Instrument [Line Items]
ABS Issued, Net	$ 4,430,130,000	$ 2,971,109,000
Number of Series \| series	22	17
Asset-backed securities issued \| Sequoia \| Revision of Prior Period, Accounting Standards Update, Adjustment
Debt Instrument [Line Items]
ABS Issued, Net	$ (622,522,000)	$ (682,477,000)
Asset-backed securities issued \| Sequoia \| Deferred Debt Issuance Costs
Debt Instrument [Line Items]
Unamortized debt discount and deferred debt issuance costs	$ 0	$ 0
Asset-backed securities issued \| Sequoia \| Minimum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	2.67%	2.57%
Asset-backed securities issued \| Sequoia \| Maximum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	6.24%	6.13%
Asset-backed securities issued \| Sequoia \| Certificates with principal balance
Debt Instrument [Line Items]
ABS Issued, Net	$ 5,000,540,000	$ 3,595,715,000
Asset-backed securities issued \| Sequoia \| Interest-only certificates at fair value
Debt Instrument [Line Items]
ABS Issued, Net	52,112,000	57,871,000
Asset-backed securities issued \| Net investments in consolidated CAFL Term entities
Debt Instrument [Line Items]
ABS Issued, Net	$ 3,362,978,000	$ 3,115,807,000
Number of Series \| series	21	19
Asset-backed securities issued \| Net investments in consolidated CAFL Term entities \| Revision of Prior Period, Accounting Standards Update, Adjustment
Debt Instrument [Line Items]
ABS Issued, Net	$ (209,740,000)	$ (323,995,000)
Asset-backed securities issued \| Net investments in consolidated CAFL Term entities \| Deferred Debt Issuance Costs
Debt Instrument [Line Items]
Unamortized debt discount and deferred debt issuance costs	$ (1,935,000)	$ (7,376,000)
Asset-backed securities issued \| Net investments in consolidated CAFL Term entities \| Minimum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	2.34%	2.34%
Asset-backed securities issued \| Net investments in consolidated CAFL Term entities \| Maximum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	7.89%	5.92%
Asset-backed securities issued \| Net investments in consolidated CAFL Term entities \| Certificates with principal balance
Debt Instrument [Line Items]
ABS Issued, Net	$ 3,472,825,000	$ 3,322,250,000
Asset-backed securities issued \| Net investments in consolidated CAFL Term entities \| Interest-only certificates at fair value
Debt Instrument [Line Items]
ABS Issued, Net	101,828,000	124,928,000
Asset-backed securities issued \| Freddie Mac SLST
Debt Instrument [Line Items]
ABS Issued, Net	$ 1,265,777,000	$ 1,222,150,000
Number of Series \| series	3	3
Debt instrument, face amount	$ 182,000,000	$ 86,000,000
Asset-backed securities issued \| Freddie Mac SLST \| Revision of Prior Period, Accounting Standards Update, Adjustment
Debt Instrument [Line Items]
ABS Issued, Net	(72,742,000)	(99,072,000)
Asset-backed securities issued \| Freddie Mac SLST \| Deferred Debt Issuance Costs
Debt Instrument [Line Items]
Unamortized debt discount and deferred debt issuance costs	$ (3,994,000)	$ (758,000)
Asset-backed securities issued \| Freddie Mac SLST \| Minimum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	3.50%	3.50%
Asset-backed securities issued \| Freddie Mac SLST \| Maximum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	7.50%	4.75%
Asset-backed securities issued \| Freddie Mac SLST \| Certificates with principal balance
Debt Instrument [Line Items]
ABS Issued, Net	$ 1,328,657,000	$ 1,306,652,000
Asset-backed securities issued \| Freddie Mac SLST \| Interest-only certificates at fair value
Debt Instrument [Line Items]
ABS Issued, Net	13,856,000	15,328,000
Asset-backed securities issued \| Freddie Mac K-Series
Debt Instrument [Line Items]
ABS Issued, Net	$ 391,977,000	$ 392,785,000
Range of weighted average interest rates, by series (as a percent)	3.55%	3.41%
Number of Series \| series	1	1
Asset-backed securities issued \| Freddie Mac K-Series \| Revision of Prior Period, Accounting Standards Update, Adjustment
Debt Instrument [Line Items]
ABS Issued, Net	$ (14,985,000)	$ (25,319,000)
Asset-backed securities issued \| Freddie Mac K-Series \| Deferred Debt Issuance Costs
Debt Instrument [Line Items]
Unamortized debt discount and deferred debt issuance costs	0	0
Asset-backed securities issued \| Freddie Mac K-Series \| Certificates with principal balance
Debt Instrument [Line Items]
ABS Issued, Net	402,400,000	410,725,000
Asset-backed securities issued \| Freddie Mac K-Series \| Interest-only certificates at fair value
Debt Instrument [Line Items]
ABS Issued, Net	4,562,000	7,379,000
Asset-backed securities issued \| HEI
Debt Instrument [Line Items]
ABS Issued, Net	$ 222,488,000	$ 100,710,000
Range of weighted average interest rates, by series (as a percent)		3.78%
Number of Series \| series	2	1
Asset-backed securities issued \| HEI \| Revision of Prior Period, Accounting Standards Update, Adjustment
Debt Instrument [Line Items]
ABS Issued, Net	$ (10,643,000)	$ (8,252,000)
Asset-backed securities issued \| HEI \| Deferred Debt Issuance Costs
Debt Instrument [Line Items]
Unamortized debt discount and deferred debt issuance costs	$ 0	0
Asset-backed securities issued \| HEI \| Minimum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	3.86%
Asset-backed securities issued \| HEI \| Maximum
Debt Instrument [Line Items]
Range of weighted average interest rates, by series (as a percent)	6.70%
Asset-backed securities issued \| HEI \| Certificates with principal balance
Debt Instrument [Line Items]
ABS Issued, Net	$ 233,131,000	108,962,000
Asset-backed securities issued \| HEI \| Interest-only certificates at fair value
Debt Instrument [Line Items]
ABS Issued, Net	0	0
Asset-backed securities issued \| CoreVest
Debt Instrument [Line Items]
Debt instrument, face amount	$ 485,000,000	$ 485,000,000