Securitized Debt Obligations, Net - Schedule of Information on Securitized Debt Obligations (Detail) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) loan	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) loan
Debt Instrument [Line Items]
Interest expense on securitized debt obligations	$ 44,500	$ 26,100	$ 127,600	$ 52,600
Senior CLO Securities Outstanding
Debt Instrument [Line Items]
Count | loan			3		3
Principal Balance	2,512,511		$ 2,512,511		$ 2,673,541
Book Value	2,509,254		$ 2,509,254		$ 2,664,010
Senior CLO Securities Outstanding | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			1		1
Principal Balance	803,750		$ 803,750		$ 803,750
Book Value	801,392		$ 801,392		$ 799,626
Senior CLO Securities Outstanding | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			1		1
Principal Balance	716,342		$ 716,342		$ 808,750
Book Value	716,284		$ 716,284		$ 806,757
Senior CLO Securities Outstanding | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			1		1
Principal Balance	992,419		$ 992,419		$ 1,061,041
Book Value	991,578		$ 991,578		$ 1,057,627
Underlying Collateral Assets
Debt Instrument [Line Items]
Count | loan			58		63
Principal Balance	3,156,886		$ 3,156,886		$ 3,317,916
Book Value	3,156,886		$ 3,156,886		$ 3,317,916
Underlying Collateral Assets | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			27		30
Principal Balance	1,000,000		$ 1,000,000		$ 1,000,000
Book Value	1,000,000		$ 1,000,000		$ 1,000,000
Underlying Collateral Assets | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			15		16
Principal Balance	907,592		$ 907,592		$ 1,000,000
Book Value	907,592		$ 907,592		$ 1,000,000
Underlying Collateral Assets | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			16		17
Principal Balance	1,249,294		$ 1,249,294		$ 1,317,916
Book Value	$ 1,249,294		$ 1,249,294		$ 1,317,916
LIBOR | Senior CLO Securities Outstanding
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			1.78%		1.73%
LIBOR | Senior CLO Securities Outstanding | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			1.69%		1.57%
LIBOR | Senior CLO Securities Outstanding | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			2.18%		2.14%
LIBOR | Senior CLO Securities Outstanding | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			1.57%		1.55%
LIBOR | Underlying Collateral Assets
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			3.21%		3.38%
LIBOR | Underlying Collateral Assets | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			3.35%		3.47%
LIBOR | Underlying Collateral Assets | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			3.04%		3.25%
LIBOR | Underlying Collateral Assets | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			3.25%		3.42%