Balance Sheet Parenthetical (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Tenant receivables allowance for doubtful accounts	$ 2,004	$ 1,760
Other receivables allowance for doubtful accounts	$ 1,257	$ 1,400
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	15,000,000	15,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares, issued	159,094,361	148,364,037
Common stock, shares outstanding	159,094,361	148,364,037
Preferred stock, shares outstanding Series C
Preferred stock, shares outstanding	460,000	460,000
Preferred stock, shares outstanding Series D
Preferred stock, shares outstanding	1,815,000	1,815,000