CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net sales	$ 55,281	$ 100,094	$ 172,048	$ 311,183
Cost of products sold	41,688	63,870	127,381	196,481
Gross profit	13,593	36,224	44,667	114,702
Costs and expenses:
General and administrative expenses	6,911	10,128	21,744	28,756
Selling and distribution expenses	4,705	6,983	18,720	20,531
Amortization of purchased intangible assets	369	394	1,076	1,189
Restructuring expenses, net and asset impairments	143	5,898	3,305	6,300
Total costs and expenses	12,128	23,403	44,845	56,776
Operating income (loss)	1,465	12,821	(178)	57,926
Other (expense) income:
Other (expense) income, net	(148)	170	(118)	492
Interest expense, net	(170)	(387)	(564)	(1,169)
Income (loss) before income taxes	1,147	12,604	(860)	57,249
Income tax provision (benefit)	139	5,689	(375)	17,920
Net income (loss)	$ 1,008	$ 6,915	$ (485)	$ 39,329
Net income (loss) per share
Basic (in dollars per share)	$ 0.07	$ 0.47	$ (0.03)	$ 2.67
Diluted (in dollars per share)	$ 0.07	$ 0.46	$ (0.03)	$ 2.64
Weighted average shares outstanding:
Basic (in shares)	14,820,881	14,632,276	14,759,062	14,589,655
Diluted (in shares)	14,820,881	14,851,166	14,759,062	14,800,132
Dividends declared per common share (in dollars per share)	$ 0	$ 0.125	$ 0.125	$ 0.165