Fee and Other Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Fee and Other Income [Abstract]
Tenant cleaning fees	$ 16,945	$ 15,647	$ 49,437	$ 46,479
Signage Revenue	4,783	5,085	14,252	14,746
Management and leasing fees	7,234	4,773	16,534	16,660
Lease termination fees	282	4,803	1,172	12,478
Other income	10,444	6,468	24,623	21,450
Fee and other income	39,688	36,776	106,018	111,813
Management fee income from Interstate Properties	$ 197	$ 195	$ 588	$ 586