RELATED PARTY TRANSACTIONS (Details) (USD $)			12 Months Ended					12 Months Ended			1 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012 Lead Trustee [Member]	Dec. 31, 2011 Lead Trustee [Member]	Dec. 31, 2010 Lead Trustee [Member]	Dec. 31, 2012 Unconsolidated Affiliates [Member]	Dec. 31, 2011 Unconsolidated Affiliates [Member]	Dec. 31, 2012 Core Portfolio [Member] Brandywine Portfolio [Member]	Dec. 31, 2011 Core Portfolio [Member] Brandywine Portfolio [Member]	Dec. 31, 2010 Core Portfolio [Member] Brandywine Portfolio [Member]	Feb. 28, 2010 Restricted Stock [Member] Klaff [Member]
Related Party Transaction [Line Items]
Units issued for interest in contractual rights (in shares)											250,000
Units issued for interest in contractual rights, converted (in shares)											250,000
Related party revenue								$ 800,000	$ 1,300,000	$ 800,000
Receivable from related parties	210,000	1,375,000				210,000	1,376,000
Related party transaction expense			$ 100,000	$ 100,000	$ 100,000