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, 2016	$ 141,377	$ 28,554	$ (82,860)	$ (26,044)	$ (6,101)	$ 54,926	$ 0
BALANCE (in shares) at Dec. 31, 2016	30,685,017						0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 0	0	0	(11,484)	0	(11,484)	$ 0
Employee pension plan adjustments	0	0	0	0	1,591	1,591	0
Derivative qualifying as cash flow hedge						0
Stock-based compensation expense
Restricted stock	$ 0	1,220	0	0	0	1,220	$ 0
Restricted stock (in shares)	128,810						0
Net share settlement for equity-based compensation	$ 0	(440)	0	0	0	(440)	$ 0
Net share settlement for equity-based compensation (in shares)	(189,420)						0
BALANCE at Dec. 31, 2017	$ 141,377	29,334	(82,860)	(37,528)	(4,510)	45,813	$ 0
BALANCE (in shares) at Dec. 31, 2017	30,624,407						0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 0	0	0	(6,545)	0	(6,545)	$ 0
Employee pension plan adjustments	0	0	0	0	448	448	0
Derivative qualifying as cash flow hedge						0
Stock-based compensation expense
Restricted stock	$ 0	522	0	0	0	522	$ 0
Restricted stock (in shares)	135,568						0
Net share settlement for equity-based compensation	$ 0	(372)	0	0	0	(372)	$ 0
Net share settlement for equity-based compensation (in shares)	(207,642)						0
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	30,552,333					30,552,333	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 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
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)
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	31,142,251					31,142,251	12,700