SHAREHOLDERS' EQUITY - OPTIONS AND RESTRICTED SHARE UNITS ROLL FORWARD (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
June 30 2018
Aggregate intrinsic value
Percentage of restricted share units vesting June 30, 2018	50.00%
Amended and Restated 2009 Stock Incentive Plan | Stock options, employees and directors
Number of options
Options outstanding at beginning of year (in shares)	1,689,555
Options granted (in shares)	508,588
Options exercised (in shares)	(49,577)
Options expired (in shares)	(90,704)
Options outstanding at end of year (in shares)	2,057,862	1,689,555
Options vested at end of year (in shares)	1,297,409
Weighted average exercise price
Options outstanding at beginning of year (in dollars per share)	$ 4.02
Options granted (in dollars per share)	3.86
Options exercised (in dollars per share)	3.32
Options expired (in dollars per share)	3.16
Options outstanding at end of year (in dollars per share)	4.03	$ 4.02
Options vested at end of year (in dollars per share)	$ 4.19
Weighted average remaining contractual life
Weighted average remaining contractual life, Outstanding (in years)	6 years 1 month 13 days	6 years 22 days
Weighted average remaining contractual life, Vested (in years)	4 years 3 months 7 days
Aggregate intrinsic value
Aggregate intrinsic value, Outstanding	$ 1,384
Aggregate intrinsic value, Vested	$ 201
Amended and Restated 2009 Stock Incentive Plan | Restricted share units, employees and directors
Number of restricted share units
Restricted share units granted	247,095
Unvested at end of year (in shares)	247,095
Weighted average grant date fair value
Restricted share units granted (in dollars per share)	$ 3.32
Unvested at end of year (in dollars per share)	$ 3.32
Aggregate intrinsic value
Aggregate intrinsic value, Outstanding, exercisable	$ 914