Deferred Costs Deferred Costs (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Components of Deferred Costs Net [Abstract]
Leasing Costs, Total Cost	$ 150,128	$ 150,331
Financing Costs, Total Cost	40,117	40,246
Total Cost	190,245	190,577
Leasing Costs, Accumulated Amortization	(58,085)	(58,343)
Financing Costs, Accumulated Amortization	(12,243)	(9,991)
Total, Accumulated Amortization	70,328	68,334
Leasing, Deferred Costs, Net	92,043	91,988
Financing Costs, Deferred Costs, Net	27,874	30,255
Deferred Costs, Net	$ 119,917	$ 122,243