Segment Information Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net sales	$ 236,830	$ 223,780		$ 697,490	$ 665,790
Operating profit (loss)	28,690	29,880		85,650	96,610
Operating Segments [Member] | Packaging [Member]
Segment Reporting Information [Line Items]
Net sales	105,480	95,250		298,310	278,540
Operating profit (loss)	19,740	22,060		60,020	64,450
Operating Segments [Member] | Aerospace [Member]
Segment Reporting Information [Line Items]
Net sales	43,140	40,890		123,710	117,780
Operating profit (loss)	8,230	7,680		20,980	18,720
Operating Segments [Member] | Specialty Products [Member]
Segment Reporting Information [Line Items]
Net sales	88,210	87,640		275,470	269,470
Operating profit (loss)	8,400	8,330		29,430	28,570
Corporate, Non-Segment [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating profit (loss)	$ (7,680)	$ (8,190)		$ (24,780)	$ (15,130)	[1]
Selling, General and Administrative Expenses [Member]
Segment Reporting Information, Additional Information [Abstract]
Loss Contingency Accrual, Period Increase (Decrease)			$ (8,200)

[1] During the first quarter of 2018, the Company removed an obligation from its balance sheet, resulting in an approximate $8.2 million non-cash reduction in selling, general and administrative expenses. See Note 12, "Commitments and Contingencies," for further details.