Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Real estate properties:
Land	$ 162,843	$ 163,020
Buildings, improvements and lease intangibles	2,521,226	2,310,404
Personal property	18,221	17,919
Construction in progress	86,328	80,262
Real estate properties, Total	2,788,618	2,571,605
Less accumulated depreciation	(516,747)	(484,641)
Total real estate properties, net	2,271,871	2,086,964
Cash and cash equivalents	4,738	113,321
Mortgage notes receivable	97,381	36,599
Assets held for sale and discontinued operations, net	28,650	23,915
Other assets, net	118,382	96,510
Total assets	2,521,022	2,357,309
Liabilities:
Notes and bonds payable	1,393,537	1,407,855
Accounts payable and accrued liabilities	72,217	62,652
Liabilities of discontinued operations	518	423
Other liabilities	49,944	43,639
Total liabilities	1,516,216	1,514,569
Commitments and contingencies
Equity:
Preferred stock, $.01 par value; 50,000,000 shares authorized; none issued and outstanding
Common stock, $.01 par value; 150,000,000 shares authorized; 77,843,833 and 66,071,424 shares issued and outstanding at December 31, 2011 and December 31, 2010, respectively	779	661
Additional paid-in capital	1,894,604	1,641,379
Accumulated other comprehensive loss	(3,332)	(5,269)
Cumulative net income attributable to common stockholders	795,951	796,165
Cumulative dividends	(1,683,196)	(1,593,926)
Total stockholders' equity	1,004,806	839,010
Noncontrolling interests	0	3,730
Total equity	1,004,806	842,740
Total liabilities and equity	$ 2,521,022	$ 2,357,309