CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Loss [Member]	Total	Series A Convertible Preferred Stock [Member]
BALANCE at Dec. 31, 2019	$ 141,377	$ 30,145	$ (82,860)	$ (42,058)	$ (3,456)	$ 43,148	$ 11,982
BALANCE (in shares) at Dec. 31, 2019	25,231,710						12,700
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 0	0	0	(1,750)	0	(1,750)	$ 0
Employee pension plan adjustments	0	0	0	0	140	140	0
Derivative qualifying as cash flow hedge	0	0	0	0	(748)	(748)	0
Stock-based compensation expense
Restricted stock	$ 0	291	0	0	0	291	$ 0
Restricted stock (in shares)	1,191,262						0
Net share settlement for equity-based compensation	$ 0	(172)	0	0	0	(172)	$ 0
Net share settlement for equity-based compensation (in shares)	(58,451)						0
BALANCE at Mar. 31, 2020	$ 141,377	30,264	(82,860)	(43,808)	(4,064)	40,909	$ 11,982
BALANCE (in shares) at Mar. 31, 2020	26,364,521						12,700
BALANCE at Dec. 31, 2020	$ 141,377	30,512	(82,860)	6,203	(4,165)	91,067	$ 11,982
BALANCE (in shares) at Dec. 31, 2020	26,476,329						12,700
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 0	0	0	4,489	0	4,489	$ 0
Preferred stock dividends	0	0	0	(304)	0	(304)	0
Employee pension plan adjustments	0	0	0	0	(134)	(134)	0
Derivative qualifying as cash flow hedge	0	0	0	0	211	211	0
Stock-based compensation expense
Restricted stock	$ 0	493	0	0	0	493	$ 0
Restricted stock (in shares)	574,614						0
Net share settlement for equity-based compensation	$ 0	(962)	0	0	0	(962)	$ 0
Net share settlement for equity-based compensation (in shares)	(154,973)						0
BALANCE at Mar. 31, 2021	$ 141,377	$ 30,043	$ (82,860)	$ 10,388	$ (4,088)	$ 94,860	$ 11,982
BALANCE (in shares) at Mar. 31, 2021	26,895,970						12,700