Income Taxes - Schedule of Provision for (Benefit from) Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ (23)		$ (14)
State	51	$ 31	4
Foreign	31	109	(101)
Current income tax expense (benefit), Total	59	140	(111)
Deferred:
Federal	3,307	(1,823)	(2,536)
State	(669)	(396)	(315)
Foreign	(359)	(296)	(521)
Deferred income tax expense (benefit), Total	2,279	(2,515)	(3,372)
Change in valuation allowance	(2,291)	2,351	2,921
Total	$ 47	$ (24)	$ (562)