Aggregate Principal Amounts Due on Mortgage Notes Payable by Unconsolidated LLCs, Accounted Under Equity Method (Detail) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Dec. 31, 2015
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance		$ 28,497	$ 28,895
Equity Method Investments
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance	[1]	28,497	28,895
Equity Method Investments | FTX MOB Phase II
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance	[1]	$ 5,333	5,427
Maturity Date		2017-08
Equity Method Investments | Grayson Properties
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance	[1]	$ 14,496	14,670
Maturity Date		2021-09
Equity Method Investments | Brunswick Associates
Schedule Of Equity Method Investments [Line Items]
Mortgage Loan Balance	[1]	$ 8,668	$ 8,798
Maturity Date		2024-12

[1] All mortgage loans require monthly principal payments through maturity and include a balloon principal payment upon maturity.