Geographic Information and Major Customer and Product Data (Details 2)	3 Months Ended				12 Months Ended
	Mar. 31, 2019		Mar. 31, 2018		Dec. 31, 2018	[1]
Customer B [Member]
Revenue, Major Customer [Line Items]
Concentration risk	19.00%
Total revenues [Member] | Customer A [Member]
Revenue, Major Customer [Line Items]
Concentration risk		[1]	37.20%
Total revenues [Member] | Customer B [Member]
Revenue, Major Customer [Line Items]
Concentration risk	12.90%			[1]

[1] Less than 10%