Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Series A Preferred Stock [Member]	Dec. 31, 2012 Series A Preferred Stock [Member]	Dec. 31, 2013 Series B Preferred Stock [Member]	Dec. 31, 2012 Series B Preferred Stock [Member]
REAL ESTATE ASSETS:
Accumulated depreciation on operating properties	$ 235,707	$ 255,128
Development in Process, Accumulated Depreciation	0	183
Real Estate Held for Sale, Accumulated Depreciation	21,444	2,947
Finite-Lived Intangible Assets, Accumulated Amortization	37,544	15,153
Allowance for doubtful accounts for notes and other receivables	1,827	1,743
Intangible Liabilities, Accumulated Amortization	$ 6,323	$ 12,504
Preferred stock, 20,000,000 shares authorized, $1 par value:
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred Stock, Dividend Rate, Percentage				7.75%	7.50%	7.50%
Preferred stock, shares issued			0	2,993,090	3,791,000	3,791,000
Preferred Stock, Shares Outstanding			0	2,993,090	3,791,000	3,791,000
Preferred Stock, Liquidation Preference Per Share				$ 25	$ 25	$ 25
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	193,236,454	107,660,080
Treasury stock, shares	3,570,082	3,570,082