Asset-Specific Debt (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) SecurityLoan	Dec. 31, 2020 USD ($) SecurityLoan
Financing provided
Participating Mortgage Loans [Line Items]
Count | SecurityLoan	4	4
Financing provided, Principal Balance	$ 400,699	$ 399,699
Financing provided, Book Value	$ 393,824	$ 391,269
Financing provided | LIBOR
Participating Mortgage Loans [Line Items]
Weighted Average Yield/Cost Rate	2.78%	3.48%
Collateral assets
Participating Mortgage Loans [Line Items]
Count | SecurityLoan	4	4
Collateral assets, Principal Balance	$ 446,276	$ 512,794
Collateral assets, Book Value	$ 435,727	$ 499,085
Collateral assets | LIBOR
Participating Mortgage Loans [Line Items]
Weighted Average Yield/Cost Rate	4.04%	4.65%