Securitized Debt Obligations, Net (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($) loan	Dec. 31, 2023 USD ($) loan
Debt Instrument [Line Items]
Debt instrument, variable interest rate, type [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR)	Secured Overnight Financing Rate (SOFR)
Securitized debt obligations, net
Debt Instrument [Line Items]
Count | loan	3	3
Count | loan	46	56
Principal balance	$ 1,936,967	$ 2,507,514
Principal Balance, collateral assets	2,552,403	3,151,889
Book Value	1,936,956	2,505,417
Book Value, collateral assets	$ 2,552,403	$ 3,151,889
Wtd. Avg. Yield/Cost, loan obligation	1.57%	1.79%
Wtd. Avg. Yield/Cost, collateral assets	2.98%	2.99%
Interest expense on debt	$ 157,000	$ 171,400
2021 FL4 Senior Collateralized Loan Obligation | Securitized debt obligations, net
Debt Instrument [Line Items]
Count | loan	1	1
Principal balance	$ 785,453	$ 803,750
Book Value	$ 785,442	$ 801,800
Wtd. Avg. Yield/Cost, loan obligation	1.39%	1.70%
2021 FL4 Underlying Collateral Assets | Securitized debt obligations, net
Debt Instrument [Line Items]
Count | loan	22	26
Principal Balance, collateral assets	$ 952,764	$ 1,000,000
Book Value, collateral assets	$ 952,764	$ 1,000,000
Wtd. Avg. Yield/Cost, collateral assets	2.95%	3.28%
2020 FL3 Senior Collateralized Loan Obligation | Securitized debt obligations, net
Debt Instrument [Line Items]
Count | loan	1	1
Principal balance	$ 552,664	$ 714,352
Book Value	$ 552,663	$ 714,352
Wtd. Avg. Yield/Cost, loan obligation	1.92%	2.18%
2020 FL3 Underlying Collateral Assets | Securitized debt obligations, net
Debt Instrument [Line Items]
Count | loan	12	15
Principal Balance, collateral assets	$ 743,914	$ 905,602
Book Value, collateral assets	$ 743,914	$ 905,602
Wtd. Avg. Yield/Cost, collateral assets	2.92%	2.87%
2020 FL2 Senior Collateralized Loan Obligation | Securitized debt obligations, net
Debt Instrument [Line Items]
Count | loan	1	1
Principal balance	$ 598,850	$ 989,412
Book Value	$ 598,851	$ 989,265
Wtd. Avg. Yield/Cost, loan obligation	1.50%	1.57%
2020 FL2 Underlying Collateral Assets | Securitized debt obligations, net
Debt Instrument [Line Items]
Count | loan	12	15
Principal Balance, collateral assets	$ 855,725	$ 1,246,287
Book Value, collateral assets	$ 855,725	$ 1,246,287
Wtd. Avg. Yield/Cost, collateral assets	2.79%	2.85%