Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	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)		74
Issuance of common stock under employee stock option and stock purchase plans	0
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units (in shares)		(12)
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units	(32)		(32)
Stock-based compensation	195		195
Foreign currency translation adjustments	1			1
Net loss from continuing operations	(2,390)				(2,390)
Balance at the end of the period (in shares) at Mar. 31, 2018		11,931
Balance at the end of the period at Mar. 31, 2018	17,066	$ 1	127,656	3	(110,594)
Balance at the beginning of the period (in shares) at Dec. 31, 2018		12,091
Balance at the beginning of the period at Dec. 31, 2018	11,052	$ 1	128,367	(1)	(117,315)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee stock option and stock purchase plans (in shares)		150
Issuance of common stock under employee stock option and stock purchase plans	0		0
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units (in shares)		(50)
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units	(111)		(111)
Stock-based compensation	543		543
Foreign currency translation adjustments	0
Net loss from continuing operations	(2,865)				(2,865)
Balance at the end of the period (in shares) at Mar. 31, 2019		12,191
Balance at the end of the period at Mar. 31, 2019	$ 8,433	$ 1	$ 128,799	$ (1)	$ (120,366)