Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Consolidated Balance Sheets [Abstract]
Allowance on deferred rent receivable	$ 24,574	$ 25,630
Allowance on notes, mortgages and accounts receivable	$ 19,700	$ 9,480
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	33,394,755	33,394,395