Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 Preferred Stock [Member]	Dec. 31, 2011 Preferred Stock [Member]	Dec. 31, 2011 Series F Preferred Stock [Member]	Sep. 30, 2012 Series G Preferred Stock [Member]	Dec. 31, 2011 Series G Preferred Stock [Member]	Sep. 30, 2012 Series H Preferred Stock [Member]	Dec. 31, 2011 Series H Preferred Stock [Member]	Sep. 30, 2012 Series I Preferred Stock [Member]	Sep. 30, 2012 Series J Preferred Stock [Member]
Operating real estate, accumulated depreciation (in Dollars)	$ 1,745,992	$ 1,693,090
Preferred Stock, Par Value (in Dollars per share)			$ 1.00	$ 1.00	$ 1.00	$ 1.00	$ 1.00	$ 1.00	$ 1.00	$ 1.00	$ 1.00
Preferred Stock, Shares Authorized (in Shares)			5,791,200	5,146,000	700,000	184,000	184,000	70,000	70,000	18,400	9,000
Preferred Stock, Shares Issued (in Shares)					700,000	184,000	184,000	70,000	70,000	16,000	9,000
Preferred Stock, Shares Outstanding (in Shares)					700,000	184,000	184,000	70,000	70,000	16,000	9,000
Preferred Stock, Aggregate Liquidation Preference (in Dollars)					$ 175,000	$ 460,000	$ 460,000	$ 175,000	$ 175,000	$ 400,000	$ 225,000
Common Stock, Par Value (in Dollars per share)	$ 0.01	$ 0.01
Common Stock, Shares Authorized (in Shares)	750,000,000	750,000,000
Common Stock, Shares Issued (in Shares)	407,608,794	406,937,830
Common Stock, Shares Outstanding (in Shares)	407,608,794	406,937,830