Fee and Other Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Fee and Other Income [Abstract]
BMS cleaning fees	$ 67,584	$ 61,754	$ 58,053
Signage Revenue	20,892	19,823	18,618
Management and leasing fees	21,867	21,801	21,686
Lease termination fees	2,361	16,334	14,818
Other income	31,845	30,037	33,780
Fee and other income	$ 144,549	$ 149,749	$ 146,955