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, 2017	$ 4,567		$ 14	$ 237,486	$ (232,933)
BALANCE, Shares at Dec. 31, 2017		6,000
BALANCE, Shares at Dec. 31, 2017			14,269,000
Non-cash compensation recognized on stock options and ESPP	36			36
Restricted stock grants, net of cancellations	899		$ 1	898
Restricted stock grants, net of cancellations, shares			1,124,000
Cancellation of shares for payment of withholding tax	(209)			(209)
Cancellation of shares for payment of withholding tax, shares			(94,000)
Employee stock purchase plan	5			5
Employee stock purchase plan, shares			5,000
Preferred shares converted to common shares			$ 4	(4)
Preferred shares converted to common shares, shares		(5,000)	3,645,000
Common shares issued in stock offering, net of offering costs	17,600		$ 9	17,591
Common shares issued in stock offering, net offering costs, shares			9,267,000
Issuance of warrants in stock offering	(6,792)			(6,792)
Exercise of common stock warrants, shares			26,000
Reclassification of warrants previously classified as liabilities to equity	7,604			7,604
Warrant repricing				11	(11)
Canadian tax adjustments from prior period	(2)				(2)
Preferred stock dividends	(404)				(404)
Comprehensive loss	(2,741)				(2,741)
BALANCE at Dec. 31, 2018	$ 20,563		$ 28	256,626	(236,091)
BALANCE, Shares at Dec. 31, 2018	1,345	1,000
BALANCE, Shares at Dec. 31, 2018	28,241,129		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 842	93				93
Comprehensive loss	10,722				10,722
BALANCE at Dec. 31, 2019	$ 48,684		$ 38	$ 274,041	$ (225,395)
BALANCE, Shares at Dec. 31, 2019	0
BALANCE, Shares at Dec. 31, 2019	38,475,084		38,476,000