Consolidated Statements Of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Consolidated Statements Of Comprehensive Income [Abstract]
Net sales	$ 71,745	$ 79,227	$ 135,595	$ 156,053
Cost of sales	57,069	59,782	108,427	116,331
Gross profit	14,676	19,445	27,168	39,722
Selling and general expenses	6,039	5,631	12,483	11,782
Intangibles amortization		1,416		2,161
Operating profit	8,637	12,398	14,685	25,779
Other income	1,638	997	3,270	1,892
Earnings from continuing operations before provision for income taxes	10,275	13,395	17,955	27,671
Provision for income taxes from continuing operations	2,122	2,619	3,851	5,901
Earnings from continuing operations	8,153	10,776	14,104	21,770
Earnings (loss) from discontinued operations, net of tax	3	(1)	3	(9)
Net earnings	$ 8,156	$ 10,775	$ 14,107	$ 21,761
Weighted average shares outstanding:
Basic and diluted	7,019	7,006	7,016	7,002
Earnings per share, basic and diluted:
From continuing operations	$ 1.16	$ 1.54	$ 2.01	$ 3.11
From discontinued operations	0.00	0.00	0.00	0.00
Net earnings per share	$ 1.16	$ 1.54	$ 2.01	$ 3.11
Comprehensive income:
Net earnings	$ 8,156	$ 10,775	$ 14,107	$ 21,761
Other comprehensive income, net of tax:
Unrealized gain on available-for-sale securities, net of tax	89	21	158	65
Comprehensive income	$ 8,245	$ 10,796	$ 14,265	$ 21,826
Cash dividends declared and paid per common share	$ 0.00	$ 0.00	$ 6.00	$ 6.00