Segment, Geographical and Other Revenue Information - Revenues (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of revenues by geographical area
Revenues	$ 60,594,000	$ 50,024,000	$ 48,837,000
Americas
Schedule of revenues by geographical area
Revenues	15,370,000	15,575,000	23,126,000
EMEA
Schedule of revenues by geographical area
Revenues	22,361,000	19,610,000	17,138,000
APAC
Schedule of revenues by geographical area
Revenues	22,863,000	14,839,000	$ 8,573,000
United States
Schedule of revenues by geographical area
Long-lived assets	$ 4,759,000	$ 2,815,000