Other Liabilities and Deferred Credits (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Other liabilities and deferred credits
Acquired below market leases, net	$ 54,793	$ 48,617
Prepaid rent and deferred revenue	4,538	5,008
Deferred rent expense and lease intangible	1,042	1,122
Deferred compensation	604	520
Straight-line rent liability	124	433
Other liabilities	39	108
Total other liabilities and deferred credits	$ 61,140	$ 55,808