STOCK OPTIONS - OPTION ACTIVITY (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Summary of option activity - Shares
Outstanding at the beginning of year (in shares)	2,606,737
Outstanding at the beginning of year (in dollars per shares)	$ 6.58
Granted (in shares)	1,093,009
Granted (in dollars per shares)	$ 8.67
Forfeited (in shares)	(92,997)
Forfeited (in dollars per shares)	$ 8.66
Exercised (in shares)	(353,439)
Exercised (in dollars per shares)	$ 4.28
Outstanding at the end of period (in shares)	3,253,310	2,606,737
Outstanding at the end of period (in dollars per shares)	$ 7.47	$ 6.58
Weighted Average Remaining Contractual Term - Outstanding	8 years 29 days
Aggregate Intrinsic Value - Outstanding (in dollars)	$ 3,416
Vested at the end of period (in shares)	1,349,752
Vested at the end of period (in dollars per share)	$ 6.81
Weighted Average Remaining Contractual Term - Vested	6 years 7 months 24 days
Aggregate Intrinsic Value - Vested (in dollars)	$ 2,459
Vested and expected to vest at the end of period (in shares)	2,625,248
Vested and expected to vest at the end of period (in dollars per share)	$ 7.37
Weighted Average Remaining Contractual Term - Vested and expected to vest	7 years 9 months 26 days
Aggregate Intrinsic Value - Vested and expected to vest (in dollars)	$ 3,073
Stock Option
Weighted average grant-date fair value of options granted	$ 7.37	$ 6.15	$ 7.76
Total fair value of options vested	$ 5,144	$ 2,329	$ 1,985
Total unrecognized compensation expense, related to non-vested share-based compensation arrangements	$ 8,193
Period for unrecognized compensation expense is estimated to be recognized	2 years 10 months 17 days