STOCK OPTIONS (Details 2) (Stock Options, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Stock Options
Stock options
Weighted-average grant date fair value of options granted (in dollars per share)	$ 11.49	$ 4.72
Total intrinsic value of options exercised (in dollars)	$ 107,639	$ 95,477
Shares
Outstanding at beginning of period (in shares)	11,417
Granted (in shares)	1,250	4,250
Exercised (in shares)	(6,083)
Expired and forfeited (in shares)	(1,666)
Outstanding at end of period (in shares)	4,918	11,417
Vested or expected to vest at the end of the period (in shares)	4,918
Exercisable at end of period (in shares)	916
Weighted Average Exercise Price
Outstanding at beginning of period (in dollars per shares)	$ 8.87
Granted (in dollars per share)	$ 28.25
Exercised (in dollars per share)	$ 7.56
Expired and forfeited (in dollars per share)	$ 7.77
Outstanding at end of period (in dollars per share)	$ 15.78	$ 8.87
Vested or expected to vest at the end of the period (in dollars per share)	$ 15.78
Exercisable at end of period (in dollars per share)	$ 9.81
Weighted Average Remaining Contractual Term
Outstanding at end of year	3 years 3 months 22 days
Vested or expected to vest at end of period	3 years 3 months 22 days
Exercisable at end of period	2 years 2 months 23 days
Aggregate Intrinsic Value
Outstanding at the end of the year (in dollars)	33,126
Vested or expected to vest at end of period (in dollars)	33,126
Exercisable at the end of the period (in dollars)	$ 9,846