Other Assets and Liabilities - Summary of Components of Other Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Accrued dividends payable	$ 90,642		$ 83,702
Derivative liabilities	26,164		42,263
Accrued interest payable	20,895		24,831
Accrued management and incentive fees payable	20,496		20,159
Current expected credit loss reserve for unfunded loan commitments	178,050	$ 112,694	0
Accounts payable and other liabilities	4,114		5,008
Total	177,313		175,963
Unfunded Loan Commitments [Member]
Current expected credit loss reserve for unfunded loan commitments	$ 15,002	$ 22,536	$ 0