Residential Consumer Loans - Schedule of Geographic Concentration of Residential Consumer Loans (Details) - Residential Loans Held for Investment - Geographic Concentration Risk - Loan Benchmark	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Concentration Risk [Line Items]
Concentration risk (as a percent)	100.00%	100.00%
California
Concentration Risk [Line Items]
Concentration risk (as a percent)	26.00%	25.00%
Washington
Concentration Risk [Line Items]
Concentration risk (as a percent)	12.00%	16.00%
Texas
Concentration Risk [Line Items]
Concentration risk (as a percent)	8.00%	8.00%
Colorado
Concentration Risk [Line Items]
Concentration risk (as a percent)	6.00%	4.00%
Florida
Concentration Risk [Line Items]
Concentration risk (as a percent)	5.00%	7.00%
Illinois
Concentration Risk [Line Items]
Concentration risk (as a percent)	3.00%	2.00%
New Jersey
Concentration Risk [Line Items]
Concentration risk (as a percent)	2.00%	2.00%
New York
Concentration Risk [Line Items]
Concentration risk (as a percent)	1.00%	1.00%
Maryland
Concentration Risk [Line Items]
Concentration risk (as a percent)	0.00%	1.00%
Other states (none greater than 5%)
Concentration Risk [Line Items]
Concentration risk (as a percent)	37.00%	34.00%
Sequoia Choice Securitization Entities
Concentration Risk [Line Items]
Concentration risk (as a percent)	100.00%	100.00%
Sequoia Choice Securitization Entities | California
Concentration Risk [Line Items]
Concentration risk (as a percent)	31.00%	33.00%
Sequoia Choice Securitization Entities | Washington
Concentration Risk [Line Items]
Concentration risk (as a percent)	8.00%	7.00%
Sequoia Choice Securitization Entities | Texas
Concentration Risk [Line Items]
Concentration risk (as a percent)	10.00%	11.00%
Sequoia Choice Securitization Entities | Colorado
Concentration Risk [Line Items]
Concentration risk (as a percent)	6.00%	7.00%
Sequoia Choice Securitization Entities | Florida
Concentration Risk [Line Items]
Concentration risk (as a percent)	7.00%	5.00%
Sequoia Choice Securitization Entities | Illinois
Concentration Risk [Line Items]
Concentration risk (as a percent)	2.00%	3.00%
Sequoia Choice Securitization Entities | New Jersey
Concentration Risk [Line Items]
Concentration risk (as a percent)	2.00%	1.00%
Sequoia Choice Securitization Entities | New York
Concentration Risk [Line Items]
Concentration risk (as a percent)	2.00%	2.00%
Sequoia Choice Securitization Entities | Maryland
Concentration Risk [Line Items]
Concentration risk (as a percent)	1.00%	2.00%
Sequoia Choice Securitization Entities | Other states (none greater than 5%)
Concentration Risk [Line Items]
Concentration risk (as a percent)	31.00%	29.00%
Freddie Mac SLST
Concentration Risk [Line Items]
Concentration risk (as a percent)	100.00%	100.00%
Freddie Mac SLST | California
Concentration Risk [Line Items]
Concentration risk (as a percent)	14.00%	14.00%
Freddie Mac SLST | Washington
Concentration Risk [Line Items]
Concentration risk (as a percent)	2.00%	2.00%
Freddie Mac SLST | Texas
Concentration Risk [Line Items]
Concentration risk (as a percent)	3.00%	3.00%
Freddie Mac SLST | Colorado
Concentration Risk [Line Items]
Concentration risk (as a percent)	1.00%	1.00%
Freddie Mac SLST | Florida
Concentration Risk [Line Items]
Concentration risk (as a percent)	10.00%	10.00%
Freddie Mac SLST | Illinois
Concentration Risk [Line Items]
Concentration risk (as a percent)	6.00%	5.00%
Freddie Mac SLST | New Jersey
Concentration Risk [Line Items]
Concentration risk (as a percent)	7.00%	7.00%
Freddie Mac SLST | New York
Concentration Risk [Line Items]
Concentration risk (as a percent)	11.00%	11.00%
Freddie Mac SLST | Maryland
Concentration Risk [Line Items]
Concentration risk (as a percent)	5.00%	5.00%
Freddie Mac SLST | Other states (none greater than 5%)
Concentration Risk [Line Items]
Concentration risk (as a percent)	41.00%	42.00%