CONDENSED CONSOLIDATED STATEMENTS OF MEZZANINE EQUITY AND STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Redeemable Preferred Stock	Common stock	Treasury Stock	Additional paid-in capital	Accumulated other comprehensive income (loss)	Accumulated deficit
Redeemable Preferred stock, beginning balance (in shares) at Dec. 31, 2018	0
Redeemable Preferred stock, beginning balance at Dec. 31, 2018	$ 0
Beginning balance (in shares) at Dec. 31, 2018			2,025,000
Beginning balance at Dec. 31, 2018	25,800		$ 0	$ (5,728)	$ 145,430	$ (22)	$ (113,880)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	112				112
Shares issued under stock incentive plans, net of shares withheld for employee taxes (in shares)			6,000
Shares issued under stock incentive plans, net of shares withheld for employee taxes	(24)				(24)
Reclassification of tax provision impact	22					22
Net loss	$ (1,657)						(1,657)
Redeemable Preferred stock, ending balance (in shares) at Mar. 31, 2019	0
Redeemable Preferred stock,ending balance at Mar. 31, 2019	$ 0
Ending balance (in shares) at Mar. 31, 2019			2,031,000
Ending balance at Mar. 31, 2019	$ 24,253		$ 0	(5,728)	145,518	0	(115,537)
Redeemable Preferred stock, beginning balance (in shares) at Dec. 31, 2018	0
Redeemable Preferred stock, beginning balance at Dec. 31, 2018	$ 0
Beginning balance (in shares) at Dec. 31, 2018			2,025,000
Beginning balance at Dec. 31, 2018	25,800		$ 0	(5,728)	145,430	(22)	(113,880)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (4,370)
Redeemable Preferred stock, ending balance (in shares) at Sep. 30, 2019	1,916,000
Redeemable Preferred stock,ending balance at Sep. 30, 2019	$ 19,156
Ending balance (in shares) at Sep. 30, 2019			2,048,000
Ending balance at Sep. 30, 2019	$ 21,672		$ 0	(5,728)	145,672	0	(118,272)
Redeemable Preferred stock, beginning balance (in shares) at Mar. 31, 2019	0
Redeemable Preferred stock, beginning balance at Mar. 31, 2019	$ 0
Beginning balance (in shares) at Mar. 31, 2019			2,031,000
Beginning balance at Mar. 31, 2019	24,253		$ 0	(5,728)	145,518	0	(115,537)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	190				190
Shares issued under stock incentive plans, net of shares withheld for employee taxes (in shares)			9,000
Shares issued for fractional shares in conjunction with reverse stock split (in shares)			2,000
Reclassification of tax provision impact	(22)						(22)
Net loss	$ (1,209)						(1,209)
Redeemable Preferred stock, ending balance (in shares) at Jun. 30, 2019	0
Redeemable Preferred stock,ending balance at Jun. 30, 2019	$ 0
Ending balance (in shares) at Jun. 30, 2019			2,042,000
Ending balance at Jun. 30, 2019	23,212		$ 0	(5,728)	145,708	0	(116,768)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	114				114
Shares issued under stock incentive plans, net of shares withheld for employee taxes (in shares)			6,000
Issuance of preferred stock	$ 19,156
Issuance of preferred stock (in shares)	1,916,000
Fees payable on issuance of preferred stock	$ (150)				(150)
Net loss	$ (1,504)						(1,504)
Redeemable Preferred stock, ending balance (in shares) at Sep. 30, 2019	1,916,000
Redeemable Preferred stock,ending balance at Sep. 30, 2019	$ 19,156
Ending balance (in shares) at Sep. 30, 2019			2,048,000
Ending balance at Sep. 30, 2019	$ 21,672		$ 0	(5,728)	145,672	$ 0	(118,272)
Redeemable Preferred stock, beginning balance (in shares) at Dec. 31, 2019		1,916,000
Redeemable Preferred stock, beginning balance at Dec. 31, 2019		$ 19,602
Beginning balance (in shares) at Dec. 31, 2019	2,050,659		2,050,000
Beginning balance at Dec. 31, 2019	$ 21,095		$ 0	(5,728)	145,352		(118,529)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	109				109
Shares issued under stock incentive plans, net of shares withheld for employee taxes (in shares)			5,000
Accrued dividend on redeemable preferred stock	(484)	$ 484
Net loss	(2,953)						(2,953)
Redeemable Preferred stock, ending balance (in shares) at Mar. 31, 2020		1,916,000
Redeemable Preferred stock,ending balance at Mar. 31, 2020		$ 20,086
Ending balance (in shares) at Mar. 31, 2020			2,055,000
Ending balance at Mar. 31, 2020	$ 17,767		$ 0	(5,728)	144,977		(121,482)
Redeemable Preferred stock, beginning balance (in shares) at Dec. 31, 2019		1,916,000
Redeemable Preferred stock, beginning balance at Dec. 31, 2019		$ 19,602
Beginning balance (in shares) at Dec. 31, 2019	2,050,659		2,050,000
Beginning balance at Dec. 31, 2019	$ 21,095		$ 0	(5,728)	145,352		(118,529)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (6,000)
Redeemable Preferred stock, ending balance (in shares) at Sep. 30, 2020		1,916,000
Redeemable Preferred stock,ending balance at Sep. 30, 2020		$ 21,041
Ending balance (in shares) at Sep. 30, 2020	4,750,951		4,751,000
Ending balance at Sep. 30, 2020	$ 19,117		$ 0	(5,728)	149,374		(124,529)
Redeemable Preferred stock, beginning balance (in shares) at Mar. 31, 2020		1,916,000
Redeemable Preferred stock, beginning balance at Mar. 31, 2020		$ 20,086
Beginning balance (in shares) at Mar. 31, 2020			2,055,000
Beginning balance at Mar. 31, 2020	17,767		$ 0	(5,728)	144,977		(121,482)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	151				151
Shares issued under stock incentive plans, net of shares withheld for employee taxes (in shares)			42,000
Shares issued under stock incentive plans, net of shares withheld for employee taxes	(13)				(13)
Accrued dividend on redeemable preferred stock	(484)	$ 484
Net proceeds from sale of common stock and warrants (in shares)			2,450,000
Net proceeds from sale of common stock and warrants	4,203				4,203
Proceeds from exercise of overallotment and warrants (in shares)			145,000
Proceeds from exercise of the over-allotment options and warrants	773				773
Net loss	(1,287)						(1,287)
Redeemable Preferred stock, ending balance (in shares) at Jun. 30, 2020		1,916,000
Redeemable Preferred stock,ending balance at Jun. 30, 2020		$ 20,570
Ending balance (in shares) at Jun. 30, 2020			4,692,000
Ending balance at Jun. 30, 2020	21,110		$ 0	(5,728)	149,607		(122,769)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	122				122
Shares issued under stock incentive plans, net of shares withheld for employee taxes (in shares)			6,000
Accrued dividend on redeemable preferred stock	(474)	474
Equity issuance costs		$ (3)
Proceeds from exercise of overallotment and warrants (in shares)			53,000
Proceeds from exercise of the over-allotment options and warrants	119				119
Net loss	$ (1,760)						(1,760)
Redeemable Preferred stock, ending balance (in shares) at Sep. 30, 2020		1,916,000
Redeemable Preferred stock,ending balance at Sep. 30, 2020		$ 21,041
Ending balance (in shares) at Sep. 30, 2020	4,750,951		4,751,000
Ending balance at Sep. 30, 2020	$ 19,117		$ 0	$ (5,728)	$ 149,374		$ (124,529)