CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Real estate properties
Land and buildings	$ 3,038,553	$ 2,537,039
Less accumulated depreciation	(580,373)	(470,420)
Real estate properties - net	2,458,180	2,066,619
Mortgage notes receivable - net	238,621	238,675
Real estate properties, total	2,696,801	2,305,294
Other investments - net	47,339	52,957
Total investments held, continuing operations	2,744,140	2,358,251
Assets held for sale - net	1,020	2,461
Total investments	2,745,160	2,360,712
Cash and cash equivalents	1,711	351	6,921	2,170
Restricted cash	36,660	34,112
Accounts receivable - net	125,180	100,664
Other assets	73,294	61,473
Total assets	2,982,005	2,557,312
LIABILITIES AND STOCKHOLDERS' EQUITY
Revolving line of credit	258,000	272,500
Secured borrowings	366,538	303,610
Unsecured borrowings - net	1,200,394	975,290
Accrued expenses and other liabilities	145,744	127,428
Total liabilities	1,970,676	1,678,828
Stockholders' equity:
Common stock $.10 par value authorized - 200,000 shares issued and outstanding - 112,393 shares as of December 31, 2012 and 103,410 as of December 31, 2011	11,239	10,341
Common stock - additional paid-in-capital	1,664,855	1,471,381
Cumulative net earnings	754,128	633,430
Cumulative dividends paid	(1,418,893)	(1,236,668)
Total stockholders' equity	1,011,329	878,484	1,004,066	865,227
Total liabilities and stockholders' equity	$ 2,982,005	$ 2,557,312