Consolidated Statements of Shareholders Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Contributed Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning Balance at Dec. 31, 2020	$ 423,682	$ 311,190	$ 41,654	$ 539,281	$ (95,921)	$ (372,522)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	(41,866)			(41,866)
Changes in fair market value of derivatives, net of tax	311				311
Changes in unrealized pension cost, net of tax	91,081				91,081
Cumulative translation adjustment, net of tax	4				4
Cash dividends	(5,173)			(5,173)
Acquired shares for treasury stock	(8,786)					(8,786)
Issued shares on vesting of restricted stock units	(1,502)	3,430	(4,932)
Stock compensation	5,827		5,827
Ending Balance at Dec. 31, 2021	463,578	314,620	42,549	492,242	(4,525)	(381,308)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	59,575			59,575
Changes in fair market value of derivatives, net of tax	3,499				3,499
Changes in unrealized pension cost, net of tax	1,203				1,203
Cumulative translation adjustment, net of tax	(848)				(848)
Cash dividends	(5,114)			(5,114)
Acquired shares for treasury stock	(21,447)					(21,447)
Issued shares on vesting of restricted stock units	(1,525)	2,183	(3,708)
Stock compensation	7,303		7,303
Ending Balance at Dec. 31, 2022	506,224	316,803	46,144	546,703	(671)	(402,755)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	60,532			60,532
Changes in fair market value of derivatives, net of tax	(505)				(505)
Changes in unrealized pension cost, net of tax	120				120
Cumulative translation adjustment, net of tax	5,320				5,320
Cash dividends	(5,003)			(5,003)
Acquired shares for treasury stock	(41,285)					(41,285)
Issued shares on vesting of restricted stock units	(3,263)	2,466	(5,729)
Stock compensation	4,682		4,682
Ending Balance at Dec. 31, 2023	$ 526,822	$ 319,269	$ 45,097	$ 602,232	$ 4,264	$ (444,040)