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
Beginning balance (in shares) at Dec. 31, 2018			2,025,000
Beginning balance at Dec. 31, 2018	$ 25,800			$ (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 unrealized gains on equity securities to retained earnings	22					22
Net loss	(1,657)						(1,657)
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, 2019		1,916,000
Redeemable Preferred stock, beginning balance at Dec. 31, 2019	$ 19,602	$ 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	0	(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	1,915,637	1,916,000
Redeemable Preferred stock,ending balance at Mar. 31, 2020	$ 20,086	$ 20,086
Ending balance (in shares) at Mar. 31, 2020	2,055,158		2,055,000
Ending balance at Mar. 31, 2020	$ 17,767		$ 0	$ (5,728)	$ 144,977	$ 0	$ (121,482)