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 and Loans Payable, Net, Carrying Amount	$ 677,890		$ 763,616
Senior Unsecured Notes ,Net, Carrying Amount	445,916		474,150
Unsecured Credit Facility, Carrying Amount	173,000	[1]	98,000	[1]
Total, Carrying Amount	1,296,806		1,335,766
Mortgage Loans Payable, Net, Fair Value	684,914		814,915
Senior Unsecured Notes, Net, Fair Value	482,781		516,943
Unsecured Credit Facility, Fair Value	173,000		98,192
Total, Fair Value	$ 1,340,695		$ 1,430,050

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