Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Net sales	$ 170,572	$ 138,741	$ 307,290	$ 249,385
Cost of sales	125,120	104,537	227,879	190,241
Gross profit	(45,452)	(34,204)	(79,411)	(59,144)
Research and development costs	4,661	5,464	9,505	10,384
Selling, general and administrative expenses	23,965	21,828	44,992	43,569
Restructuring charges	31	277	31	277
Gain on sale of property	0	0	0	(6,175)
Income from operations	16,795	6,635	24,883	11,089
Interest expense	(779)	(721)	(1,467)	(1,523)
Other (expense) income, net	(1,724)	113	(2,496)	660
Earnings before provision for income taxes	14,292	6,027	20,920	10,226
Benefit from income taxes	(2,746)	(1,853)	(1,182)	(854)
Net earnings available to common stockholders	17,038	7,880	22,102	11,080
Common Class A [Member]
Net earnings available to common stockholders	$ 2,793	$ 1,299	$ 3,614	$ 1,822
Net earnings per common share:
Class A common share - basic and diluted (in dollars per share)	$ 1.30	$ 0.61	$ 1.68	$ 0.85
Weighted-average number of shares outstanding:
Class A common share - basic and diluted (in shares)	2,144	2,145	2,145	2,145
Common Class B [Member]
Net earnings available to common stockholders	$ 14,245	$ 6,581	$ 18,488	$ 9,258
Net earnings per common share:
Class A common share - basic and diluted (in dollars per share)	$ 1.37	$ 0.64	$ 1.78	$ 0.91
Weighted-average number of shares outstanding:
Class A common share - basic and diluted (in shares)	10,362	10,237	10,368	10,220