Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Net sales	$ 209,330	$ 202,290	$ 622,530	$ 608,490
Operating profit (loss)	28,120	17,790	70,110	52,900
Packaging [Member]
Segment Reporting Information [Line Items]
Net sales	89,560	90,330	259,260	258,550
Operating profit (loss)	23,090	20,090	61,480	59,340
Aerospace [Member]
Segment Reporting Information [Line Items]
Net sales	48,550	47,430	141,550	132,020
Operating profit (loss)	7,760	6,660	19,690	13,670
Energy [Member]
Segment Reporting Information [Line Items]
Net sales	40,440	38,230	124,860	122,930
Operating profit (loss)	1,240	(1,870)	(2,550)	(8,570)
Engineered Components [Member]
Segment Reporting Information [Line Items]
Net sales	30,780	26,300	96,860	94,990
Operating profit (loss)	3,310	3,180	13,000	12,620
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating profit (loss)	$ (7,280)	$ (10,270)	$ (21,510)	$ (24,160)