Fair Value Measurements (Details 4) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Trust's financial assets for which the fair value option was elected
Financial Assets at Fair Value	$ 39,464	$ 34,165
Fair Value Securities [Member] | REIT Preferred Shares [Member]
Trust's financial assets for which the fair value option was elected
Financial Assets at Fair Value		4,277
Fair Value Securities [Member] | REIT Common shares [Member]
Trust's financial assets for which the fair value option was elected
Financial Assets at Fair Value	34,079	24,579
Fair Value Loan Securities [Member]
Trust's financial assets for which the fair value option was elected
Financial Assets at Fair Value	$ 5,385	$ 5,309