Residential Loans - Quarterly Activity of Residential Loans Held-for-Sale (Details) - Residential Loans $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) securitization	Mar. 31, 2022 USD ($) securitization
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal balance of loans acquired	$ 53,046	$ 2,115,191
Principal balance of loans sold	173,153	1,827,364
Principal balance of loans transferred to HFI	657,295	687,192
Net market valuation gains (losses) recorded	7,178	(31,451)
Legacy Sequoia
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Principal balance of loans acquired	$ 0	$ 102,000
Number of seasoned securities | securitization	0	3