ACQUISITION (Narrative) (Details) - USD ($)
$ in Thousands
 1 Months Ended 12 Months Ended
Aug. 13, 2013
May 31, 2016
May 18, 2016
Apr. 22, 2016
Apr. 18, 2016
Mar. 31, 2016
Jan. 31, 2016
Nov. 30, 2015
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2013
Dec. 26, 2013
Business Acquisition, Contingent Consideration [Line Items]                          
Cash paid for acquisition $ 10,000                     $ 10,000  
Customer relations and goodwill                 $ 7,026 $ 7,026 $ 4,688    
Business Combination, Bargain Purchase, Gain Recognized, Amount                 0 10,515 0    
Payments to Acquire Businesses, Gross 10,000                     $ 10,000  
Amortized cost of Intangible Assets                 3,184 2,517 $ 1,382    
Inventory Valuation Reserves                 232 218      
Prevision [Member]                          
Business Acquisition, Contingent Consideration [Line Items]                          
Contingent payments cap               $ 250          
Ownership interests               100.00%          
Total consideration               $ 1,100          
Net identifiable liabilities               200          
Customer relations and goodwill               $ 1,300          
Business Acquisition, Percentage of Voting Interests Acquired               100.00%          
Business Combination, Consideration Transferred               $ 1,100          
Cost of Services, Amortization                 44 51      
Amortized cost of Intangible Assets                 1,185 1,229      
Leaders in Community Alternatives [Member]                          
Business Acquisition, Contingent Consideration [Line Items]                          
Ownership interests             100.00%            
Total consideration             $ 2,918            
Business Acquisition, Percentage of Voting Interests Acquired             100.00%            
Business Combination, Consideration Transferred             $ 2,918            
Cost of Services, Amortization                 56 61      
Amortized cost of Intangible Assets                 2,537 2,592      
Safend Ltd [Member]                          
Business Acquisition, Contingent Consideration [Line Items]                          
Additional contingent consideration           $ 1,500              
Ownership interests           100.00%              
Business Acquisition, Percentage of Voting Interests Acquired           100.00%              
Business Combination, Bargain Purchase, Gain Recognized, Amount           $ 3,662              
Cost of Services, Amortization                 618 619      
Amortized cost of Intangible Assets                 2,528 3,146      
PowaPOS [Member]                          
Business Acquisition, Contingent Consideration [Line Items]                          
Payments to Acquire Productive Assets         $ 1,174                
Receivables, Net, Current         138                
Finite-lived Intangible Assets Acquired         493                
Inventory Valuation Reserves         $ 543                
Alvarion Technologies Ltd. [Member]                          
Business Acquisition, Contingent Consideration [Line Items]                          
Cash paid for acquisition     $ 1,000                    
Total consideration     1,425                    
Business Combination, Consideration Transferred     1,425                    
Property, Plant, and Equipment, Salvage Value                 4,440 4,664      
Business Combination, Bargain Purchase, Gain Recognized, Amount     6,853                    
Payments to Acquire Businesses, Gross     1,000                    
Business Combination, Contingent Consideration, Liability     1,000                    
Amortized cost of Intangible Assets                 $ 225 $ 140      
Finite-lived Intangible Assets Acquired     $ 1,026                    
Earn-out Agreement [Member]                          
Business Acquisition, Contingent Consideration [Line Items]                          
Maximum contingent payments $ 12,500     $ 3,550                 $ 12,500
Additional contingent consideration   $ 2,050   $ 1,500