SEGMENTS INFORMATION (Major Customers) (Details) - Customer Concentration Risk	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Sales Revenue, Segment [Member] | Operating Segments
Revenue, Major Customer [Line Items]
Number of customers	0	0
Accounts Receivable | Billed Revenues
Revenue, Major Customer [Line Items]
Number of customers	0		0
Accounts Receivable | Unbilled Revenues
Revenue, Major Customer [Line Items]
Number of customers	0		0