Consolidated Balance Sheets (Parentheticals) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accounts receivable. allowance	$ 3,597	$ 2,945
Straight-line rent receivable, allowance	7,447	7,260
Deferred financing costs, accumulated amortization	59,109	46,407
Deferred leasing and other costs, accumulated amortization	$ 292,334	$ 269,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	3,176	3,618
Preferred stock, shares outstanding	3,176	3,618
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	400,000	400,000
Common stock, shares issued	252,927	252,195
Common stock, shares outstanding	252,927	252,195