Segment Information Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Net sales	$ 206,730	$ 182,790
Operating profit (loss)	21,110	19,830
Operating Segments [Member] | Packaging [Member]
Segment Reporting Information [Line Items]
Net sales	132,090	100,050
Operating profit (loss)	21,300	18,280
Operating Segments [Member] | Aerospace [Member]
Segment Reporting Information [Line Items]
Net sales	44,610	48,920
Operating profit (loss)	4,500	5,080
Operating Segments [Member] | Specialty Products [Member]
Segment Reporting Information [Line Items]
Net sales	30,030	33,820
Operating profit (loss)	4,520	3,430
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating profit (loss)	$ (9,210)	$ (6,960)