Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - 9 months ended Sep. 30, 2018 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Balance at the beginning of the period (in shares) at Dec. 31, 2017		11,869
Balance at the beginning of the period at Dec. 31, 2017	$ 19,292	$ 1	$ 127,493	$ 2	$ (108,204)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock option and stock purchase plans (in shares)		227
Issuance of common stock under employee stock option and stock purchase plans	21		21
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units (in shares)		(25)
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units	(60)		(60)
Stock-based compensation	706		706
Foreign currency translation adjustments	(3)			(3)
Net loss from continuing operations	(6,114)				(6,114)
Balance at the end of the period (in shares) at Sep. 30, 2018		12,071
Balance at the end of the period at Sep. 30, 2018	$ 13,842	$ 1	$ 128,160	$ (1)	$ (114,318)