Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Net Sales	$ 556,405	$ 579,975	$ 1,107,823	$ 1,231,411
Cost of Sales	486,853	513,578	967,990	1,091,454
Gross Profit	69,552	66,397	139,833	139,957
Operating Expenses:
Selling	11,828	11,109	23,216	24,176
Administrative	24,569	22,589	47,259	45,228
Research, development and technical services	14,093	14,105	28,349	29,243
Deferred compensation expense	395	743	2,173	2,245
Total Operating expenses	50,885	48,546	100,997	100,892
Business restructuring expense		42		199
Operating Income	18,667	17,809	38,836	38,866
Other Income (Expense):
Interest, net	(2,661)	(3,865)	(5,732)	(6,687)
Other, net (Note 15)	1,200	2,370	3,562	4,038
Nonoperating Income (Expense), Total	(1,461)	(1,495)	(2,170)	(2,649)
Income Before Provision for Income Taxes	17,206	16,314	36,666	36,217
Provision for Income Taxes	7,685	3,630	13,252	7,391
Net Income	$ 9,521	$ 12,684	$ 23,414	$ 28,826
Net Income Per Common Share (Note 10):
Basic	$ 0.42	$ 0.56	$ 1.03	$ 1.27
Diluted	$ 0.42	$ 0.55	$ 1.02	$ 1.25
Shares Used to Compute Net Income Per Common Share (Note 10):
Basic	22,827	22,768	22,825	22,763
Diluted	22,936	22,945	22,942	22,970