SHAREHOLDERS' EQUITY - OPTIONS AND RESTRICTED SHARE UNITS ROLL FORWARD (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Dec. 12, 2017
2009 Plan | Stock options, all inclusive recipients
Aggregate intrinsic value
Shares available for future grant (in shares)			805,593
Amended 2009 Stock Plan | Stock options, employees and directors
Number of options
Options outstanding at beginning of period (in shares)	2,057,862
Options forfeited (in shares)	(122,663)
Options outstanding at end of period (in shares)	1,935,199	2,057,862
Options vested at end of period (in shares)	1,266,337
Weighted average exercise price
Options outstanding at beginning of period (in dollars per share)	$ 4.03
Options outstanding at end of period (in dollars per share)	4.03	$ 4.03
Options vested at end of period (in dollars per share)	$ 4.17
Weighted average remaining contractual life
Weighted average remaining contractual life, Outstanding (in years)	6 years	6 years 1 month 13 days
Weighted average remaining contractual life, Vested (in years)	4 years 3 months 26 days
Aggregate intrinsic value
Aggregate intrinsic value, Outstanding	$ 139	$ 1,384
Aggregate intrinsic value, Vested	$ 81
Amended and Restated 2009 Stock Incentive Plan
Aggregate intrinsic value
Shares available for future grant (in shares)	1,385,938
Amended and Restated 2009 Stock Incentive Plan | Restricted share units, employees and directors
Number of restricted share units
Unvested at beginning of period (in shares)	247,095
RSUs forfeited	(11,850)
Unvested at end of period (in shares)	235,245	247,095
Weighted average grant date fair value
Unvested at beginning of period (in dollars per share)	$ 3.32
RSUs forfeited (in dollars per share)
Unvested at end of period (in dollars per share)	$ 3.33	$ 3.32
Aggregate intrinsic value
Aggregate intrinsic value, Unvested at beginning of period	$ 914
Aggregate intrinsic value, RSU's forfeited
Aggregate intrinsic value, Unvested at end of the period	$ 765	$ 914