SIGNIFICANT CUSTOMERS AND GEOGRAPHIC NET REVENUES (Customer and Credit Risk Concentration) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2018 USD ($) customers	Dec. 31, 2017 USD ($) customers	Dec. 31, 2016 USD ($) customers
Concentration Risk [Line Items]
Revenues | $	$ 93,307	$ 110,085	$ 109,482	$ 103,081	$ 108,249	$ 111,255	$ 107,563	$ 104,688	$ 415,955	$ 431,755	$ 389,668
Distributors [Member]
Concentration Risk [Line Items]
Revenues | $									$ 313,900	$ 330,900	$ 292,600
Credit Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Concentration risk percentage benchmark for total accounts receivable	10.00%				10.00%				10.00%	10.00%
Number of major customers | customers									10	10
Concentration Risk, Percentage									64.00%	64.00%
Credit Concentration Risk | Accounts Receivable | Avnet
Concentration Risk [Line Items]
Concentration Risk, Percentage									17.00%	18.00%
Credit Concentration Risk | Accounts Receivable | Powertech Distribution Ltd.
Concentration Risk [Line Items]
Concentration Risk, Percentage									11.00%
Customer Concentration Risk | Net Revenues
Concentration Risk [Line Items]
Number of major customers | customers									10	10	10
Concentration Risk, Percentage									10.00%	10.00%	10.00%
Concentration risk percentage of net revenue									56.00%	54.00%	60.00%
Customer Concentration Risk | Net Revenues | Avnet
Concentration Risk [Line Items]
Concentration risk percentage of net revenue									14.00%	16.00%	18.00%
Customer Concentration Risk | Net Revenues | Powertech Distribution Ltd.
Concentration Risk [Line Items]
Concentration risk percentage of net revenue											10.00%