CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ 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	$ 207,085	$ 205,274	$ 553,772	$ 644,110
Cost of sales	169,155	168,918	448,856	520,423
Gross profit	37,930	36,356	104,916	123,687
Selling, product development and administrative expenses	32,227	28,909	95,418	94,011
Impairment of goodwill and other long-lived assets	0	0	61,109	0
Restructuring expenses	14,984	0	14,984	0
Operating (loss) income	(9,281)	7,447	(66,595)	29,676
Employee benefit plans settlement expenses	0	186	385	25,701
Interest expense	4,537	3,666	11,870	11,025
Other expense (income), net	276	(885)	106	(1,359)
(Loss) income before income taxes	(14,094)	4,480	(78,956)	(5,691)
Income tax (benefit) expense	(2,334)	1,574	(4,944)	(5,519)
Income from equity method investment	(50)	(98)	(24)	(120)
Net (loss) income	$ (11,710)	$ 3,004	$ (73,988)	$ (52)
(Loss) earnings per share:
Basic (USD per share)	$ (0.67)	$ 0.17	$ (4.26)	$ (0.00)
Diluted (USD per share)	$ (0.67)	$ 0.17	$ (4.26)	$ (0.00)
Weighted average number of common shares outstanding:
Basic (shares)	17,384	17,270	17,364	17,264
Diluted (shares)	17,384	17,330	17,364	17,264