Indebtedness - Summary of Indebtedness at Estimated Fair Value (Detail) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015
Debt Disclosure [Line Items]
Total, Carrying Amount	[1]	$ 1,487,865	$ 1,442,411
Total, Fair Value		1,539,349	1,495,687
Mortgages
Debt Disclosure [Line Items]
Total, Carrying Amount	[1]	509,076	564,955
Mortgage Loans Payable, Net, Fair Value		537,245	595,964
Senior Unsecured Notes
Debt Disclosure [Line Items]
Total, Carrying Amount	[1]	205,289	364,956
Senior Unsecured Debt, Net, Fair Value		227,684	386,253
Unsecured Term Loan
Debt Disclosure [Line Items]
Total, Carrying Amount	[1]	460,000	460,000
Unsecured Term Loan, Fair Value		460,920	460,970
Unsecured Credit Facility
Debt Disclosure [Line Items]
Total, Carrying Amount	[1]	313,500	52,500
Unsecured Credit Facility, Fair Value		$ 313,500	$ 52,500

[1] The carrying amounts include unamortized premiums and discounts and exclude unamortized deferred financing costs.