CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Net sales	$ 43,203	$ 110,954	$ 116,766	$ 211,089
Cost of products sold	36,599	68,881	85,696	132,611
Gross profit	6,604	42,073	31,070	78,478
Costs and expenses:
General and administrative expenses	6,707	9,460	14,831	18,628
Selling and distribution expenses	5,488	7,239	14,015	13,548
Amortization of purchased intangible assets	353	397	707	795
Restructuring expenses, net and asset impairments	2,046	324	3,162	402
Total costs and expenses	14,594	17,420	32,715	33,373
Operating (loss) income	(7,990)	24,653	(1,645)	45,105
Other (expense) income:
Other (expense) income, net	(85)	343	32	322
Interest expense, net	(156)	(409)	(394)	(782)
(Loss) income before income taxes	(8,231)	24,587	(2,007)	44,645
Income tax (benefit) provision	(2,583)	7,343	(514)	12,231
Net (loss) income	$ (5,648)	$ 17,244	$ (1,493)	$ 32,414
Net (loss) income per share
Basic (in dollars per share)	$ (0.38)	$ 1.17	$ (0.10)	$ 2.20
Diluted (in dollars per share)	$ (0.38)	$ 1.15	$ (0.10)	$ 2.17
Weighted average shares outstanding:
Basic (in shares)	14,832,242	14,647,019	14,745,661	14,624,718
Diluted (in shares)	14,832,242	14,899,987	14,745,661	14,849,816
Dividends declared per common share (in dollars per share)	$ 0	$ 0.02	$ 0.125	$ 0.04