Deferred Costs Deferred Costs (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Components of Deferred Costs Net [Abstract]
Leasing Costs, Total Cost	$ 159,113	$ 150,331
Financing Costs, Total Cost	40,116	40,246
Total Cost	199,229	190,577
Leasing Costs, Accumulated Amortization	(59,569)	(58,343)
Financing Costs, Accumulated Amortization	(13,400)	(9,991)
Total, Accumulated Amortization	72,969	68,334
Leasing, Deferred Costs, Net	99,544	91,988
Financing Costs, Deferred Costs, Net	26,716	30,255
Deferred Costs, Net	$ 126,260	$ 122,243