Other Assets and Liabilities - Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, Other Assets and Other Liabilities Disclosure [Abstract]
Accrued interest receivable	$ 214,835	$ 189,569
Loan portfolio payments held by servicer	152,423	68,489
Collateral deposited under derivative agreements	103,500	103,110
Accounts receivable and other assets	2,420	1,318
Derivative assets	1,890	7,349
Prepaid expenses	1,020	1,067
Total	$ 476,088	$ 370,902