Other Assets and Liabilities - Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Other Assets And Liabilities Disclosure [Abstract]
Accrued interest receivable	$ 176,049	$ 214,835
Loan portfolio payments held by servicer	131,347	152,423
Collateral deposited under derivative agreements	49,080	103,500
Real estate intangible assets, net	18,602	0
Accounts receivable and other assets	8,157	2,420
Derivative assets	7,026	1,890
Prepaid expenses	646	1,020
Total	$ 390,907	$ 476,088