LOANS HELD FOR INVESTMENT (Details 3) (USD $)	9 Months Ended			1 Months Ended	9 Months Ended	0 Months Ended	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Jun. 30, 2013 Apartment Building in Arlington, VA	Sep. 30, 2013 Apartment Building in Arlington, VA	Aug. 21, 2013 Office Building in Boston, MA	Sep. 30, 2013 Office Building in Boston, MA	Sep. 30, 2013 Office Building in Boston, MA
Change in the activity of loan portfolio
Balance at the beginning of the period	$ 353,500,000
Initial funding	368,116,000
Receipt of origination fee, net of costs	(3,694,000)
Additional funding	20,769,000
Amortizing payments	(150,000)
Origination fee accretion	1,854,000	171,000
Loan payoff	(48,070,000)			(13,400,000)		(34,700,000)
Balance at the end of the period	692,325,000
Gain (loss) on repayment of stretch senior mortgage loan on the apartment building in Arlington, VA					0	0
Accelerated loan origination fees and costs included in interest income					146,000		298,000	298,000
Impairment charges recognized	$ 0		$ 0