Other Assets and Liabilities - Summary of Components of Other Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Accrued dividends payable	$ 106,824	$ 106,455
Accrued interest payable	70,724	80,263
Secured debt repayments pending servicer remittance	49,903	60,585
Current expected credit loss reserve for unfunded loan commitments	13,624	16,380
Accounts payable and other liabilities	7,742	9,726
Derivative liabilities	328	119,665
Other liabilities	278,027	426,904
Related Party
Related Party Transaction [Line Items]
Accrued management and incentive fees payable	$ 28,882	$ 33,830