Segment Reporting - Summary of Sales by Product (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Total revenue	$ 125,300	$ 112,287	$ 78,479
Endpoint ICs
Revenue:
Total revenue	91,699	86,218	52,854
Systems
Revenue:
Total revenue	$ 33,601	$ 26,069	$ 25,625