Indebtedness - Summary of Indebtedness at Estimated Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Debt Disclosure [Abstract]
Mortgage Loans Payable, Net, Carrying Amount	$ 580,215		$ 656,329
Senior Unsecured Notes, Carrying Amount	445,916		474,150
Unsecured Credit Facility, Carrying Amount	173,000	[1]	98,000	[1]
Total, Carrying Amount	1,199,131		1,228,479
Mortgage Loans Payable, Net, Fair Value	585,449		699,903
Senior Unsecured Notes, Net, Fair Value	482,781		516,943
Unsecured Credit Facility, Fair Value	173,000		98,192
Total, Fair Value	$ 1,241,230		$ 1,315,038

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