Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets [Abstract]
Real Estate and Other Assets Held for Sale, Accumulated Depreciation and Amortization	$ 34,443	$ 148,407
Accrued Interest on Mortgage Loan Payable	0	6
Deferred Costs, Leasing, Accumulated Amortization	415	2,642
General Partner Preferred Units, Issued	1,550	1,550
General Partner Preferred Units, Outstanding	1,550	1,550
General Partner Preferred Units Liquidation Preference	$ 275,000	$ 275,000
General Partner Units, Issued	86,807,402	68,841,296
General Partner Units, Outstanding	86,807,402	68,841,296
Limited Partners' Units, Issued	5,237,367	5,363,151
Limited Partners' Units, Outstanding	5,237,367	5,363,151