Securitized Debt Obligations, Net - Schedule of Information on Securitized Debt Obligations (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) loan	Dec. 31, 2020 USD ($) loan
Financing provided
Debt Instrument [Line Items]
Count | loan	3	4
Principal Balance	$ 2,855,625	$ 2,940,638
Book Value	$ 2,838,062	$ 2,922,499
Financing provided | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	1
Principal Balance	$ 803,750
Book Value	$ 797,373
Financing provided | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	1	1
Principal Balance	$ 808,750	$ 808,750
Book Value	$ 804,096	$ 800,993
Financing provided | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	1	1
Principal Balance	$ 1,243,125	$ 1,243,125
Book Value	$ 1,236,593	$ 1,233,464
Financing provided | 2017 FL1 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan		1
Principal Balance		$ 404,929
Book Value		$ 483,113
Financing provided | 2017 Single Asset Securitization
Debt Instrument [Line Items]
Count | loan		1
Principal Balance		$ 483,834
Book Value		$ 404,929
Collateral assets
Debt Instrument [Line Items]
Count | loan	73	72
Principal Balance	$ 3,500,000	$ 3,785,528
Book Value	$ 3,500,000	$ 3,785,100
Collateral assets | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	34
Principal Balance	$ 1,000,000
Book Value	$ 1,000,000
Collateral assets | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	18	25
Principal Balance	$ 1,000,000	$ 1,000,000
Book Value	$ 1,000,000	$ 1,000,000
Collateral assets | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan	21	31
Principal Balance	$ 1,500,000	$ 1,500,000
Book Value	$ 1,500,000	$ 1,500,000
Collateral assets | 2017 FL1 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan		15
Principal Balance		$ 666,334
Book Value		$ 666,334
Collateral assets | 2017 Single Asset Securitization
Debt Instrument [Line Items]
Count | loan		1
Principal Balance		$ 619,194
Book Value		$ 618,766
LIBOR | Financing provided
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	1.69%	1.70%
LIBOR | Financing provided | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	1.66%
LIBOR | Financing provided | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	2.10%	2.08%
LIBOR | Financing provided | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	1.45%	1.44%
LIBOR | Financing provided | 2017 FL1 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost		1.83%
LIBOR | Financing provided | 2017 Single Asset Securitization
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost		1.63%
LIBOR | Collateral assets
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	3.20%	3.25%
LIBOR | Collateral assets | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	3.42%
LIBOR | Collateral assets | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	3.06%	3.09%
LIBOR | Collateral assets | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	3.15%	3.17%
LIBOR | Collateral assets | 2017 FL1 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost		3.39%
LIBOR | Collateral assets | 2017 Single Asset Securitization
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost		3.57%