Securitized Debt Obligations, Net (Detail) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) loan	Dec. 31, 2023 USD ($) loan
Debt Instrument [Line Items]
Interest expense on securitized debt obligations	$ 41,500	$ 171,400
Senior CLO Securities Outstanding
Debt Instrument [Line Items]
Count | loan	3	3
Principal Balance	$ 2,329,456	$ 2,507,514
Book Value	$ 2,328,073	$ 2,505,417
Senior CLO Securities Outstanding | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	1	1
Principal Balance	$ 785,452	$ 803,750
Book Value	$ 784,138	$ 801,800
Senior CLO Securities Outstanding | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	1	1
Principal Balance	$ 689,384	$ 714,352
Book Value	$ 689,384	$ 714,352
Senior CLO Securities Outstanding | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	1	1
Principal Balance	$ 854,620	$ 989,412
Book Value	$ 854,551	$ 989,265
Underlying Collateral Assets
Debt Instrument [Line Items]
Count | loan	56	56
Principal Balance	$ 2,973,832	$ 3,151,889
Book Value	$ 2,973,832	$ 3,151,889
Underlying Collateral Assets | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	26	26
Principal Balance	$ 981,703	$ 1,000,000
Book Value	$ 981,703	$ 1,000,000
Underlying Collateral Assets | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	15	15
Principal Balance	$ 880,634	$ 905,602
Book Value	$ 880,634	$ 905,602
Underlying Collateral Assets | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	15	15
Principal Balance	$ 1,111,495	$ 1,246,287
Book Value	$ 1,111,495	$ 1,246,287
LIBOR | Senior CLO Securities Outstanding
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	1.82%	1.79%
LIBOR | Senior CLO Securities Outstanding | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	1.70%	1.70%
LIBOR | Senior CLO Securities Outstanding | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	2.19%	2.18%
LIBOR | Senior CLO Securities Outstanding | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	1.62%	1.57%
LIBOR | Underlying Collateral Assets
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	2.94%	2.99%
LIBOR | Underlying Collateral Assets | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	3.16%	3.28%
LIBOR | Underlying Collateral Assets | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	2.86%	2.87%
LIBOR | Underlying Collateral Assets | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	2.85%	2.85%