Securitized Debt Obligations, Net - Schedule of Information on Securitized Debt Obligations (Detail) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2019 USD ($) Loans	Dec. 31, 2018 USD ($) Loans
Financing Provided [Member]
Debt Instrument [Line Items]
Count | Loans	[1]	2	2
Principal Balance	[1]	$ 1,292,120	$ 1,292,120
Book Value	[1]	$ 1,287,364	$ 1,285,471
Financing Provided [Member] | Collateralized Loan Obligations [Member]
Debt Instrument [Line Items]
Count | Loans		1	1
Principal Balance		$ 817,500	$ 817,500
Book Value		$ 812,857	$ 811,023
Term	[2]	2035-06	2035-06
Financing Provided [Member] | Single Asset Securitization [Member]
Debt Instrument [Line Items]
Count | Loans		1	1
Principal Balance		$ 474,620	$ 474,620
Book Value		$ 474,507	$ 474,448
Term	[2]	2033-06	2033-06
Collateral Assets [Member]
Debt Instrument [Line Items]
Count | Loans		24	27
Principal Balance		$ 1,695,956	$ 1,682,297
Book Value		$ 1,693,272	$ 1,678,770
Wtd. Avg. Yield/Cost	[3]		6.19%
Collateral Assets [Member] | Collateralized Loan Obligations [Member]
Debt Instrument [Line Items]
Count | Loans		23	26
Principal Balance		$ 1,000,000	$ 1,000,000
Book Value		$ 1,000,000	$ 1,000,000
Wtd. Avg. Yield/Cost	[3]		6.25%
Term	[2]	2022-06	2022-04
Collateral Assets [Member] | Single Asset Securitization [Member]
Debt Instrument [Line Items]
Count | Loans	[4]	1	1
Principal Balance	[4]	$ 695,956	$ 682,297
Book Value	[4]	$ 693,272	$ 678,770
Term	[2],[4]	2023-06	2023-06
LIBOR [Member] | Financing Provided [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[1],[3]	1.68%	1.71%
LIBOR [Member] | Financing Provided [Member] | Collateralized Loan Obligations [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[3]	1.70%	1.74%
LIBOR [Member] | Financing Provided [Member] | Single Asset Securitization [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[3]	1.65%	1.65%
LIBOR [Member] | Collateral Assets [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[3]	3.64%
LIBOR [Member] | Collateral Assets [Member] | Collateralized Loan Obligations [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[3]	3.67%
LIBOR [Member] | Collateral Assets [Member] | Single Asset Securitization [Member]
Debt Instrument [Line Items]
Wtd. Avg. Yield/Cost	[3],[4]	3.60%	3.60%

[1] During the three and six months ended June 30, 2019, we recorded $8.4 million and $20.9 million, respectively, of interest expense related to our securitized debt obligations. During the three and six months ended June 30, 2018, we recorded $12.0 million and $23.1 million, respectively, of interest expense related to our securitized debt obligations.

[2] Loan term represents weighted-average final maturity, assuming all extension options are exercised by the borrower. Repayments of securitized debt obligations are tied to timing of the related collateral loan asset repayments. The term of these obligations represents the rated final distribution date of the securitizations.

[3] As of June 30, 2019, all of our loans financed by securitized debt obligations earned a floating rate of interest. As of December 31, 2018, 98% of our loans financed by securitized debt obligations earned a floating rate of interest. In addition to cash coupon, all-in yield includes the amortization of deferred origination and extension fees, loan origination costs, purchase discounts, and accrual of exit fees. All-in yield for the total portfolio assume applicable floating benchmark rates for weighted-average calculation.

[4] The collateral assets for the 2017 Single Asset Securitization include the total loan amount, of which we securitized $500.0 million.