CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net sales	$ 127,416	$ 140,710	$ 252,805	$ 258,961
Cost of sales	107,532	111,696	209,361	208,814
Gross profit	19,884	29,014	43,444	50,147
Selling, general and administrative expenses	18,764	18,306	38,564	38,998
Gain on sale of property	(4,257)	0	(4,257)	0
Restructuring charges	424	41	1,370	45
Income from operations	4,953	10,667	7,767	11,104
Interest expense	(1,381)	(1,349)	(2,820)	(2,527)
Interest income and other, net	(184)	(285)	(389)	(521)
Earnings before provision for income taxes	3,388	9,033	4,558	8,056
Provision for income taxes	421	2,399	460	2,724
Net earnings available to common stockholders	2,967	6,634	4,098	5,332
Class A Common Share [Member]
Net earnings available to common stockholders	$ 494	$ 1,141	$ 673	$ 901
Net earnings per common share:
Common share - basic and diluted (in dollars per share)	$ 0.23	$ 0.52	$ 0.31	$ 0.41
Weighted-average number of shares outstanding:
Common share - basic and diluted (in shares)	2,175	2,175	2,175	2,175
Class B Common Share [Member]
Net earnings available to common stockholders	$ 2,473	$ 5,493	$ 3,425	$ 4,431
Net earnings per common share:
Common share - basic and diluted (in dollars per share)	$ 0.24	$ 0.56	$ 0.34	$ 0.45
Weighted-average number of shares outstanding:
Common share - basic and diluted (in shares)	10,112	9,844	10,100	9,850