Segment Information - Revenue by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net	$ 16,154	$ 15,239	$ 13,412	$ 11,307	$ 12,330	$ 11,180	$ 10,282	$ 10,176	$ 56,112	$ 43,968	$ 43,259
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net									11,667	6,301	8,831
Rest of Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net									245	483	602
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net									9,546	5,809	4,817
Asia Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net									34,263	31,051	28,711
Rest of World [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue, net									$ 391	$ 324	$ 298