Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Assets
Land	$ 49,114	$ 49,114
Buildings and improvements	487,396	487,396
Construction in progress	9,864	4,983
Real estate properties, gross	546,374	541,493
Less accumulated depreciation	(150,063)	(146,698)
Real estate properties, net	396,311	394,795
Mortgage notes receivable, net	77,853	78,672
Investment in preferred stock, at cost	38,132	38,132
Cash and cash equivalents	6,927	15,886
Marketable securities	11,772	11,364
Accounts Receivable, Net	1,373	1,184
Straight-line rent receivable	9,768	8,706
Assets held for sale, net	29,381	29,381
Deferred costs and other assets	1,387	1,443
Total Assets	572,904	579,563
Liabilities and Stockholders' Equity
Long-term Line of Credit	95,300	97,300
Real estate purchase liabilities	9,478	9,478
Accounts payable and accrued expenses	2,818	3,483
Dividends Payable	18,061	24,144
Deferred income	1,633	1,673
Total Liabilities	127,290	136,078
Commitments and Contingencies
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Common stock, $.01 par value; 40,000,000 shares authorized; 27,709,611 and 27,689,392 shares issued and outstanding, respectively	278	278
Capital in excess of par value	467,110	465,678
Cumulative dividends in excess of net income	(29,363)	(29,652)
Unrealized gains on marketable securities	7,589	7,181
Total Stockholders' Equity	445,614	443,485
Total Liabilities and Stockholders' Equity	$ 572,904	$ 579,563