Other Assets and Liabilities - Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Other Assets And Liabilities Disclosure [Abstract]
Accrued interest receivable	$ 196,814	$ 214,835
Collateral deposited under derivative agreements	15,904	103,500
Accounts receivable and other assets	7,549	2,420
Derivative assets	4,878	1,890
Prepaid expenses	650	1,020
Loan portfolio payments held by servicer	0	152,423
Total	$ 225,795	$ 476,088