Segment and Geographic Information (Tables)

12 Months Ended

Dec. 31, 2018

Segment Reporting [Abstract]

Summary of Revenue by Geographic Area Based on the Customers' Location

The following table sets forth revenue by geographic area based on the customers’ location (in thousands): 

	Year Ended December 31,
	2018		2017		2016
United States	$	34,231	$	11,506	$	1,106
Germany		13,727		—		—
Rest of world		33,004		22,536		21,131
Total revenue	$	80,962	$	34,042	$	22,237