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 Income (Loss) [Member]	Total	Series A Convertible Preferred Stock [Member]
BALANCE at Dec. 31, 2018	$ 141,377	$ 29,484	$ (82,860)	$ (44,073)	$ (4,062)	$ 39,866	$ 0
BALANCE (in shares) at Dec. 31, 2018	24,641,792						0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 0	0	0	2,015	0	2,015	$ 0
Employee pension plan adjustments	0	0	0	0	780	780	0
Derivative qualifying as cash flow hedge	0	0	0	0	(174)	(174)	0
Issuance of series A convertible preferred stock, net of issuance costs	$ 0	0	0	0	0	0	$ 11,982
Issuance of series A convertible preferred stock, net of issuance costs (in shares)	0						12,700
Stock-based compensation expense
Restricted stock	$ 0	679	0	0	0	679	$ 0
Restricted stock (in shares)	595,436						0
Net share settlement for equity-based compensation	$ 0	(18)	0	0	0	(18)	$ 0
Net share settlement for equity-based compensation (in shares)	(5,518)						0
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	$ 0	0	0	48,565	0	48,565	$ 0
Preferred stock dividends	0	(1,074)	0	(304)	0	(1,378)	0
Employee pension plan adjustments	0	0	0	0	(6)	(6)	0
Derivative qualifying as cash flow hedge	0	0	0	0	(703)	(703)	0
Stock-based compensation expense
Restricted stock	$ 0	1,686	0	0	0	1,686	$ 0
Restricted stock (in shares)	1,319,734						0
Net share settlement for equity-based compensation	$ 0	(245)	0	0	0	(245)	$ 0
Net share settlement for equity-based compensation (in shares)	(75,115)						0
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