Summary of the Financial Position of the Entities Accounted for Using the Equity Method (Detail) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Assets:
Real estate, net	$ 1,493,832	$ 1,393,274
Other assets	82,916	67,278
Total assets	1,576,748	1,460,552
Liabilities and partners' capital:
Mortgage notes payable and credit facility	(1,035,234)	(965,931)
Other liabilities	(30,390)	(24,835)
Partners' capital	(511,124)	(469,786)
Total liabilities and partners' capital	$ (1,576,748)	$ (1,460,552)