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, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) loan	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($) loan
Debt Instrument [Line Items]
Credit spread adjustment (percentage)	0.11%		0.11%		0.11%
Interest expense on securitized debt obligations	$ 26,100	$ 10,700	$ 52,600	$ 35,200
Financing provided
Debt Instrument [Line Items]
Count | loan			3		3
Principal Balance	2,855,625		$ 2,855,625		$ 2,855,625
Book Value	2,844,032		$ 2,844,032		$ 2,838,062
Financing provided | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			1		1
Principal Balance	803,750		$ 803,750		$ 803,750
Book Value	799,063		$ 799,063		$ 797,373
Financing provided | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			1		1
Principal Balance	808,750		$ 808,750		$ 808,750
Book Value	806,068		$ 806,068		$ 804,096
Financing provided | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			1		1
Principal Balance	1,243,125		$ 1,243,125		$ 1,243,125
Book Value	1,238,901		$ 1,238,901		$ 1,236,593
Collateral assets
Debt Instrument [Line Items]
Count | loan			65		73
Principal Balance	3,500,000		$ 3,500,000		$ 3,500,000
Book Value	3,500,000		$ 3,500,000		$ 3,500,000
Collateral assets | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			31		34
Principal Balance	1,000,000		$ 1,000,000		$ 1,000,000
Book Value	1,000,000		$ 1,000,000		$ 1,000,000
Collateral assets | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			16		18
Principal Balance	1,000,000		$ 1,000,000		$ 1,000,000
Book Value	1,000,000		$ 1,000,000		$ 1,000,000
Collateral assets | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Count | loan			18		21
Principal Balance	1,500,000		$ 1,500,000		$ 1,500,000
Book Value	$ 1,500,000		$ 1,500,000		$ 1,500,000
LIBOR
Debt Instrument [Line Items]
One-month USD LIBOR	3.14%		3.14%		0.10%
LIBOR | Financing provided
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			1.62%		1.69%
LIBOR | Financing provided | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			1.57%		1.66%
LIBOR | Financing provided | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			2.03%		2.10%
LIBOR | Financing provided | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			1.39%		1.45%
LIBOR | Collateral assets
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			3.37%		3.20%
LIBOR | Collateral assets | 2021 FL4 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			3.51%		3.42%
LIBOR | Collateral assets | 2020 FL3 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			3.21%		3.06%
LIBOR | Collateral assets | 2020 FL2 Collateralized Loan Obligation
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost			3.39%		3.15%
Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
30 day average compounded SOFR reference rate	3.04%		3.04%		0.05%