Indebtedness - Summary of Indebtedness at Estimated Fair Value (Detail) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Debt Disclosure [Line Items]
Mortgage Loans Payable, Net, Carrying Amount		$ 564,955	$ 599,985
Senior Unsecured Debt, Net, Carrying Amount		364,956	364,861
Unsecured Term Loan, Carrying Amount		460,000	200,000
Unsecured Credit Facility, Carrying Amount		52,500	185,000
Total, Carrying Amount		1,442,411	1,349,846
Total, Fair Value		1,495,687	1,422,460
Mortgages
Debt Disclosure [Line Items]
Mortgage Loans Payable, Net, Carrying Amount		564,955	599,985
Mortgage Loans Payable, Net, Fair Value		595,964	640,818
Senior Unsecured Notes
Debt Disclosure [Line Items]
Senior Unsecured Debt, Net, Carrying Amount		364,956	364,861
Senior Unsecured Debt, Net, Fair Value		386,253	395,320
Unsecured Term Loan
Debt Disclosure [Line Items]
Unsecured Term Loan, Carrying Amount		460,000	200,000
Unsecured Term Loan, Fair Value		460,970	200,575
Unsecured Credit Facility
Debt Disclosure [Line Items]
Unsecured Credit Facility, Carrying Amount	[1]	52,500	185,000
Unsecured Credit Facility, Fair Value		$ 52,500	$ 185,747

[1] The maturity date may be extended an additional year at our election, subject to certain restrictions.