Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified			12 Months Ended		6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Dec. 31, 2012 Series A Preferred Stock [Member]	Jun. 30, 2013 Series A Preferred Stock [Member]	Jun. 30, 2013 Series B Preferred Stock [Member]	Dec. 31, 2012 Series B Preferred Stock [Member]
PROPERTIES:
Accumulated depreciation on operating properties	$ 221,331	$ 255,128
Development in Process, Accumulated Depreciation	0	183
Real Estate Held for Sale, Accumulated Depreciation	12,139	2,947
Allowance for doubtful accounts for notes and other receivables	$ 1,700	$ 1,743
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
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	124,257,723	107,660,080
Treasury stock, shares	3,570,082	3,570,082
Preferred stock, dividend rate			7.75%		7.50%	7.50%
Preferred stock, shares issued			2,993,090	0	3,791,000	3,791,000
Preferred stock, shares outstanding			2,993,090	0	3,791,000	3,791,000
Preferred stock, liquidation preference			$ 25		$ 25	$ 25