Goodwill and Other Intangible Assets - Goodwill Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Balance, beginning	$ 334,640	$ 316,650
Goodwill, Acquired During Period	92,390	18,400
Goodwill, Impairment Loss	(126,840)
Goodwill reassigned between segments	0	0
Foreign currency translation	3,780	(410)
Balance, ending	303,970	334,640
Packaging [Member]
Goodwill [Roll Forward]
Balance, beginning	181,650	163,660
Goodwill, Acquired During Period	49,130	18,400
Goodwill, Impairment Loss	0
Goodwill reassigned between segments	0	0
Foreign currency translation	3,780	(410)
Balance, ending	234,560	181,650
Aerospace [Member]
Goodwill [Roll Forward]
Balance, beginning	133,690	146,430
Goodwill, Acquired During Period	43,260	0
Goodwill, Impairment Loss	(126,840)
Goodwill reassigned between segments	12,740	(12,740)
Foreign currency translation	0	0
Balance, ending	62,850	133,690
Specialty Products [Member]
Goodwill [Roll Forward]
Balance, beginning	19,300	6,560
Goodwill, Acquired During Period	0	0
Goodwill, Impairment Loss	0
Goodwill reassigned between segments	(12,740)	12,740
Foreign currency translation	0	0
Balance, ending	$ 6,560	$ 19,300