Condensed Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
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]
Stock Issued During Period, Shares, Employee Stock Purchase Plans			150
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)			(50)
Common stock withheld in lieu of income tax withholding on vesting of restricted stock units	(111)			(111)
Stock-based compensation	543			543
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)
Balance at the beginning of the period (in shares) at Dec. 31, 2019		0	12,428
Balance at the beginning of the period at Dec. 31, 2019	3,996	$ 0	$ 1	128,872	(3)	(124,874)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, Employee Stock Purchase Plans			27
Issuance of common stock under employee stock option and stock purchase plans	0
Issuance of common stock and warrants (in shares)			3,442
Issuance of common stock and warrants	2,750		$ 1	2,749
Offering costs on issuance of common stock and warrants	(474)			(474)
Warrant liability	(1,636)			(1,636)
Conversion of notes to preferred stock	1,769			1,769
Conversion of notes to preferred stock		2,709
Stock-based compensation	20			20
Net loss from continuing operations	(541)					(541)
Balance at the end of the period (in shares) at Mar. 31, 2020		2,709	15,897
Balance at the end of the period at Mar. 31, 2020	$ 5,884	$ 0	$ 2	$ 131,300	$ (3)	$ (125,415)