Geographic Information and Major Customer and Product Data - Long-lived Assets by Geographic Region (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Long-lived assets	$ 21,065	$ 17,323
United States
Segment Reporting Information [Line Items]
Long-lived assets	11,394	7,612
Israel
Segment Reporting Information [Line Items]
Long-lived assets	7,682	7,834
France
Segment Reporting Information [Line Items]
Long-lived assets	1,205	1,243
Other
Segment Reporting Information [Line Items]
Long-lived assets	$ 784	$ 634