Loans Receivable, Net - Activity Relating to Loans Receivable Portfolio (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Principal Balance
Beginning balance	$ 23,923,719
Loan fundings	301,678
Loan repayments, sales, and cost-recovery proceeds	(582,248)
Charge-offs	(73,176)
Transfer to real estate owned	(60,203)	$ 0
Transfer to other assets	(8,800)
Payment-in-kind interest, net of interest received	2,329
Unrealized (loss) gain on foreign currency translation	(185,417)
Ending balance	23,317,882
Deferred Fees / Other Items
Beginning balance	(136,707)
Loan repayments, sales, and cost-recovery proceeds	(16,818)
Charge-offs	12,163
Unrealized (loss) gain on foreign currency translation	909
Deferred fees and other items	(4,550)
Amortization of fees and other items	16,433
Ending balance	(128,570)
Net Book Value
Beginning balance	23,787,012
Loan fundings	301,678
Loan repayments, sales, and cost-recovery proceeds	(599,066)
Charge-offs	(61,013)
Unrealized (loss) gain on foreign currency translation	(184,508)
Deferred fees and other items	(4,550)
Amortization of fees and other items	16,433
Ending balance	23,189,312
CECL reserve	(751,370)	$ (336,591)	$ (576,936)	$ (326,137)
Loans receivable, net	$ 22,437,942		$ 23,210,076