Reportable Segments (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010
Summary of assets by business segment
Cash and cash equivalents	$ 159,251	$ 40,952	$ 66,777	$ 45,257
Restricted cash	15,273	3,914
TOTAL ASSETS	866,937	733,933
Reportable Segment [Member]
Summary of assets by business segment
Operating Properties	487,667	442,209
Loan assets	175,961	217,174
REIT Securities	37,191	28,856
Cash and cash equivalents	159,251	40,952
Restricted cash	2,787	3,914
Accounts receivable and prepaids	888	510
Deferred financing costs	3,192	318
TOTAL ASSETS	$ 866,937	$ 733,933