Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Comprehensive Deficit [Member]
BALANCE at Dec. 31, 2018	$ 20,563		$ 28	$ 256,626	$ (236,091)
BALANCE, Shares at Dec. 31, 2018		1,000
BALANCE, Shares at Dec. 31, 2018			28,242,000
Non-cash compensation recognized on stock options and ESPP	43			43
Restricted stock grants, net of cancellations	1,451		$ 1	1,450
Restricted stock grants, net of cancellations, shares			1,225,000
Cancellation of shares for payment of withholding tax	(701)			(701)
Cancellation of shares for payment of withholding tax, shares			(214,000)
Employee stock purchase plan	10			10
Employee stock purchase plan, shares			4,000
Preferred shares converted to common shares			$ 1	(1)
Preferred shares converted to common shares, shares		(1,000)	1,180,000
Common shares issued in stock offering, net of offering costs	(14)			(14)
Common shares issued in connection with Smart Retail acquisition, net	5,129		$ 3	5,126
Common shares issued in connection, with Smart Retail acquisition, net, shares			2,699,000
Exercise of common stock warrants	11,457		$ 5	11,452
Exercise of common stock warrants, shares			5,327,000
Exercise of stock options	$ 50			50
Exercise of stock options, shares	13,000		13,000
Preferred stock dividends	$ (119)				(119)
Cumulative effect of adoption of ASC | ASC 842 [Member]	93				93
Net income	10,722				10,722
BALANCE at Dec. 31, 2019	$ 48,684		$ 38	274,041	(225,395)
BALANCE, Shares at Dec. 31, 2019	38,475,084		38,476,000
Non-cash compensation recognized on stock options and ESPP	$ 65			65
Restricted stock grants, net of cancellations	2,999		$ 1	2,998
Restricted stock grants, net of cancellations, shares			1,000,000
Cancellation of shares for payment of withholding tax	(1,440)			(1,440)
Cancellation of shares for payment of withholding tax, shares			(309,000)
Employee stock purchase plan	19			19
Employee stock purchase plan, shares			6,000
Exercise of common stock warrants	4,196		$ 2	4,194
Exercise of common stock warrants, shares			2,047,000
Exercise of stock options	$ 28			28
Exercise of stock options, shares	13,000		13,000
Net income	$ 4,165				4,165
BALANCE at Dec. 31, 2020	$ 58,716		$ 41	$ 279,905	$ (221,230)
BALANCE, Shares at Dec. 31, 2020	41,232,804		41,233,000