CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net sales	$ 932,886	$ 802,583	$ 898,260
Cost of sales	583,747	510,763	583,968
Gross margin	349,139	291,820	314,292
Selling, general and administrative expenses	193,153	182,283	168,682
Research and development expenses	29,904	29,320	31,685
Restructuring and impairment charges	3,570	12,987	2,485
Other operating (income) expense, net	5,330	(104)	959
Operating income	117,182	67,334	110,481
Equity income in unconsolidated joint ventures	7,032	4,877	5,319
Pension settlement charges	(534)	(55)	(53,213)
Other income (expense), net	5,136	3,513	(592)
Interest expense, net	(2,536)	(7,135)	(6,869)
Income before income tax expense	126,280	68,534	55,126
Income tax expense	18,147	18,544	7,807
Net income	$ 108,133	$ 49,990	$ 47,319
Basic earnings per share (in dollars per share)	$ 5.77	$ 2.68	$ 2.55
Diluted earnings per share (in dollars per share)	$ 5.73	$ 2.67	$ 2.53
Shares used in computing:
Basic earnings per share (in shares)	18,731	18,681	18,573
Diluted earnings per share (in shares)	18,863	18,706	18,713