Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues and other items:
Gross Sales	$ 209,517	$ 184,370	$ 605,468	$ 562,766
Other income (expense), net	391	(37,934)	9,272	(63,898)
Total revenues, net of other expenses	209,908	146,436	614,740	498,868
Costs and expenses:
Selling, general and administrative	16,767	20,420	55,422	61,654
Research and development	1,613	1,656	4,770	6,063
Amortization of identifiable intangibles	724	753	2,170	2,264
Accrued pension and post-retirement benefits	3,540	3,567	10,622	10,701
Interest expense	842	494	2,555	1,598
Asset impairments and costs associated with exit and disposal activities, net of adjustments	265	3	633	74
Goodwill, Impairment Loss	0	0	0	13,696
Total	201,771	169,354	567,436	530,484
Income (loss) from continuing operations before income taxes	8,137	(22,918)	47,304	(31,616)
Income tax expense (benefit)	1,908	(5,942)	10,728	(8,308)
Net income (loss) from continuing operations	6,229	(16,976)	36,576	(23,308)
Income (loss) from discontinued operations, net of tax	(26)	(48,237)	(104)	(53,031)
Net income (loss)	$ 6,203	$ (65,213)	$ 36,472	$ (76,339)
Basic:
Continuing operations	$ 0.19	$ (0.51)	$ 1.09	$ (0.70)
Discontinued operations	0	(1.44)	0	(1.59)
Earnings Per Share, Basic	0.19	(1.95)	1.09	(2.29)
Diluted:
Continuing operations	0.19	(0.51)	1.09	(0.70)
Discontinued operations (in USD per share)	0	(1.44)	0	(1.59)
Earnings Per Share, Diluted	$ 0.19	$ (1.95)	$ 1.09	$ (2.29)
Shares used to compute earnings (loss) per share:
Basic	33,620	33,439	33,541	33,396
Diluted	33,649	33,439	33,678	33,396
Product [Member]
Costs and expenses:
Cost of Goods and Services Sold	$ 170,756	$ 136,008	$ 470,733	$ 415,212
Shipping and Handling [Member]
Costs and expenses:
Cost of Goods and Services Sold	$ 7,264	$ 6,453	$ 20,531	$ 19,222