Segment Information Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Net sales	$ 218,990	$ 199,550	$ 425,720	$ 382,340
Operating profit (loss)	25,570	(18,150)	46,680	1,680
Operating Segments [Member] | Packaging [Member]
Segment Reporting Information [Line Items]
Net sales	139,630	128,830	271,720	228,880
Operating profit (loss)	27,850	24,040	49,150	42,320
Operating Segments [Member] | Aerospace [Member]
Segment Reporting Information [Line Items]
Net sales	44,560	42,610	89,170	91,530
Operating profit (loss)	2,120	(4,210)	6,620	870
Operating Segments [Member] | Specialty Products [Member]
Segment Reporting Information [Line Items]
Net sales	34,800	28,110	64,830	61,930
Operating profit (loss)	6,010	(5,940)	10,530	(2,510)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating profit (loss)	$ (10,410)	$ (32,040)	$ (19,620)	$ (39,000)