SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Bad debt expense	$ 53	$ (9)	$ 4	$ (1)
Antidilutive shares excluded from computation of EPS (in shares)				156,707
Reduction in retained earnings	$ (69,706)		$ (69,706)			$ (60,074)
Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reduction in retained earnings					$ 65
Reduction in prepaid taxes						$ 65