SUBSEQUENT EVENTS (Details) (USD $)	9 Months Ended		0 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Oct. 08, 2013 Subsequent events	Oct. 08, 2013 Subsequent events Common Stock
Subsequent Events
Common stock sold under the public offering				1,926,250
Share price of common stock issued under the public offering				$ 20.75
Gross proceeds from the public offering			$ 40,000,000
Common stocks sold pursuant to the option granted to the underwriters				251,250
Proceeds from public offering after deducting underwriting discounts and commissions and offering expenses	$ 5,611,000	$ 6,564,000	$ 37,500,000