Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Net sales	$ 639,813	$ 654,233
Cost of sales	423,964	470,780
Gross profit	215,849	183,453
Research and development costs	22,487	20,238
Selling, general and administrative expenses	99,091	92,342
Restructuring charges	10,114	7,322
Gain on sale of properties	(3,819)	(1,596)
Income from operations	87,976	65,147
Gain on sale of Czech Republic business	980	0
Interest expense	(2,850)	(3,379)
Other income/expense, net	(2,806)	(2,709)
Earnings before provision for income taxes	83,300	59,059
Provision for income taxes	9,469	6,370
Net earnings available to common shareholders	73,831	52,689
Common Class A [Member]
Net earnings available to common shareholders	$ 11,830	$ 8,598
Net earnings per common share:
Net earnings per common share - basic and diluted (in dollars per share)	$ 5.52	$ 4.01
Weighted-average shares outstanding:
Weighted-average number of shares outstanding - basic and diluted (in shares)	2,142	2,143
Common Class B [Member]
Net earnings available to common shareholders	$ 62,001	$ 44,091
Net earnings per common share:
Net earnings per common share - basic and diluted (in dollars per share)	$ 5.83	$ 4.24
Weighted-average shares outstanding:
Weighted-average number of shares outstanding - basic and diluted (in shares)	10,634	10,394