Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Operating real estate, accumulated depreciation	$ 2,220,455	$ 2,115,320
Preferred stock, par value (in dollars per share)	$ 1	$ 1
Preferred stock, shares authorized (in shares)	6,029,100	6,029,100
Preferred stock, shares issued (in shares)	32,000	32,000
Preferred stock, shares outstanding (in shares)	32,000	32,000
Preferred stock, aggregate liquidation preference	$ 800,000	$ 800,000
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)	425,013,233	413,430,756
Common stock,shares outstanding (in shares)	425,013,233	413,430,756