Deferred Costs (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Components of Deferred Costs Net [Abstract]
Leasing Costs, Total Cost	$ 136,932	$ 140,772
Financing Costs, Total Cost	42,019	38,929
Total Cost	178,951	179,701
Leasing Costs, Accumulated Amortization	(51,196)	(50,990)
Financing Costs, Accumulated Amortization	(9,070)	(13,349)
Total, Accumulated Amortization	(60,266)	(64,339)
Leasing Costs, Deferred Costs, net	85,736	89,782
Financing Costs, Deferred Costs, net	32,949	25,580
Deferred Costs	$ 118,685	$ 115,362