Loans Held for Investment - Changes in Carrying Value of Securitized Loans Held For Investment Carried at Fair Value (Details) - Loans Held for Investment at Fair Value - Variable Interest Entities, Primary Beneficiary - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Balance, beginning of period	$ 11,359,236	$ 12,261,926	$ 12,261,926
Transfer due to consolidation	0	$ 1,047,838	1,047,838
Purchases	1,232,969		1,615,377
Principal paydowns	(708,119)		(2,160,445)
Sales and settlements	(1,246)		(5,369)
Net periodic accretion (amortization)	(27,847)		(52,616)
Change in fair value	74,544		(1,347,475)
Balance, end of period	$ 11,929,537		$ 11,359,236