Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Nonemployees [Member] Preferred Stock [Member]	Nonemployees [Member] Common Stock [Member]	Nonemployees [Member] Additional Paid-in Capital [Member]	Nonemployees [Member] AOCI Attributable to Parent [Member]	Nonemployees [Member] Retained Earnings [Member]	Nonemployees [Member]	Employees and Directors [Member] Preferred Stock [Member]	Employees and Directors [Member] Common Stock [Member]	Employees and Directors [Member] Additional Paid-in Capital [Member]	Employees and Directors [Member] AOCI Attributable to Parent [Member]	Employees and Directors [Member] Retained Earnings [Member]	Employees and Directors [Member]	Employee [Member] Preferred Stock [Member]	Employee [Member] Common Stock [Member]	Employee [Member] Additional Paid-in Capital [Member]	Employee [Member] AOCI Attributable to Parent [Member]	Employee [Member] Retained Earnings [Member]	Employee [Member]	Conversion of Series A Preferred Stock to Common Stock [Member] Preferred Stock [Member]	Conversion of Series A Preferred Stock to Common Stock [Member] Common Stock [Member]	Conversion of Series A Preferred Stock to Common Stock [Member] Additional Paid-in Capital [Member]	Conversion of Series A Preferred Stock to Common Stock [Member] AOCI Attributable to Parent [Member]	Conversion of Series A Preferred Stock to Common Stock [Member] Retained Earnings [Member]	Conversion of Series A Preferred Stock to Common Stock [Member]	Series A Preferred Stock [Member] Preferred Stock [Member]	Series A Preferred Stock [Member] Common Stock [Member]	Series A Preferred Stock [Member] Additional Paid-in Capital [Member]	Series A Preferred Stock [Member] AOCI Attributable to Parent [Member]	Series A Preferred Stock [Member] Retained Earnings [Member]	Series A Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Dec. 31, 2016																																15,269,000
Balance at Dec. 31, 2016																																$ 153	$ 110,619		$ (103,671)	$ 7,101
Net loss																																			(7,403)	(7,403)
Issuance of common stock in connection with exercise of warrants, net of offering costs (in shares)																																21,000
Issuance of common stock in connection with exercise of warrants, net of offering costs																																	97			$ 97
Issuance of stock for option exercises (in shares)																																68,000				68,000
Issuance of stock for option exercises																																$ 1	184			$ 185
Issuance of stock to consultants for services (in shares)																																1,000
Issuance of stock to consultants for services
Vesting of restricted stock awards (in shares)		26,000
Vesting of restricted stock awards			$ 106			$ 106
Stock-based compensation expense related to employee and director stock options																																	1,867			1,867
Stock-based compensation expense related to non-employee and director stock options																																	137			137
Stock option modification																																	504			504
Conversion of Series A Preferred Stock to common stock
Balance (in shares) at Dec. 31, 2017																																15,385,000
Balance at Dec. 31, 2017																																$ 154	113,514		(111,074)	2,594
Net loss																																			(6,545)	$ (6,545)
Issuance of stock for option exercises (in shares)																																4,000				4,000
Issuance of stock for option exercises																																	11			$ 11
Stock-based compensation expense related to employee and director stock options									$ 594			$ 594
Stock option modification																																	77			77
Issuance of common stock in connection with offering (in shares)																																1,700,000
Issuance of common stock in connection with offering																																$ 17	5,967			5,984
Offering costs																																	(399)			(399)
Cumulative retrospective adjustment related to adoption of ASC 606																																			2,638	2,638
Conversion of Series A Preferred Stock to common stock
Balance (in shares) at Dec. 31, 2018																																17,089,000
Balance at Dec. 31, 2018																																$ 171	119,764		(114,981)	4,954
Net loss																																			(9,658)	(9,658)
Issuance of common stock in connection with exercise of warrants, net of offering costs (in shares)																																389,000
Issuance of common stock in connection with exercise of warrants, net of offering costs																																$ 4	616			$ 620
Issuance of stock for option exercises (in shares)																																83,000				83,000
Issuance of stock for option exercises																																	189			$ 189
Vesting of restricted stock awards (in shares)		36,000												6,000
Vesting of restricted stock awards			20			20									$ 10			$ 10
Stock-based compensation expense related to employee and director stock options																																	37			37
Stock-based compensation expense related to non-employee and director stock options			$ 334			$ 334
Stock option modification																																	105			105
Issuance of common stock in connection with offering (in shares)																																7,467,000
Issuance of common stock in connection with offering																																$ 75	3,427			3,502
Reclassification of Warrant Liability to Equity – see Note 2																																	412		(356)	56
Down round feature adjustment related to warrants																																	29		(29)
Issuance of Series A Preferred Stock and common stock warrants, net of offering costs (in shares)																															2,700,000
Issuance of Series A Preferred Stock and common stock warrants, net of offering costs																															$ 584
Conversion of Series A Preferred Stock to common stock (in shares)																			(2,700,000)
Conversion of Series A Preferred Stock to common stock																			$ (584)					(584)
Conversion of Series A Preferred Stock to common stock (in shares)																				2,700,000
Conversion of Series A Preferred Stock to common stock																				$ 27	$ 557			584
Conversion of Series A Preferred Stock to common stock																				$ 27	$ 557			$ 584
Beneficial conversion feature upon issuance of Series A Preferred Stock																											$ 800			$ 800
Deemed dividend from beneficial conversion feature of Series A Preferred Stock																											$ (800)			$ (800)
Issuance of RSUs related to employee separation agreement (in shares)																																168,000
Issuance of RSUs related to employee separation agreement																																$ 2	218			220
Balance (in shares) at Dec. 31, 2019																																27,938,000
Balance at Dec. 31, 2019																																$ 279	$ 125,718		$ (125,024)	$ 973