Goodwill and Other Intangible Assets - Goodwill Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Balance, beginning	$ 315,080	$ 378,920
Goodwill, Impairment Loss		(60,200)
Foreign currency translation	4,310	(3,640)
Balance, ending	319,390	315,080
Packaging [Member]
Goodwill [Roll Forward]
Balance, beginning	162,090	165,730
Goodwill, Impairment Loss		0
Foreign currency translation	4,310	(3,640)
Balance, ending	166,400	162,090
Aerospace [Member]
Goodwill [Roll Forward]
Balance, beginning	146,430	206,630
Goodwill, Impairment Loss		(60,200)
Foreign currency translation	0	0
Balance, ending	146,430	146,430
Energy [Member]
Goodwill [Roll Forward]
Balance, beginning	0	0
Goodwill, Impairment Loss		0
Foreign currency translation	0	0
Balance, ending	0	0
Engineered Components [Member]
Goodwill [Roll Forward]
Balance, beginning	6,560	6,560
Goodwill, Impairment Loss		0
Foreign currency translation	0	0
Balance, ending	$ 6,560	$ 6,560