Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Beneficiaries' equity:
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	11,110,883	11,095,883
Common stock, shares outstanding	10,574,554	10,559,554
Treasury stock, shares	536,329	536,329