Fee and Other Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Fee and Other Income [Abstract]
Tenant cleaning fees	$ 15,510	$ 15,423
Management and leasing fees	4,381	4,106
Lease termination fees	411	1,176
Other income	13,085	13,558
Total Fee and Other Income	33,387	34,263
Management fee income from Interstate Properties	$ 199	$ 197