Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net Sales	$ 817,740	$ 794,020	$ 863,980
Operating Profit (Loss)	88,490	(44,000)	(4,250)
Capital Expenditures	36,800	31,330	28,660
Depreciation and Amortization	46,870	44,860	43,540
Assets	1,033,200	1,051,650	1,170,300
Packaging [Member]
Segment Reporting Information [Line Items]
Net Sales	344,570	341,340	334,270
Operating Profit (Loss)	80,380	77,840	78,470
Capital Expenditures	17,140	19,880	13,670
Depreciation and Amortization	21,630	22,120	20,920
Assets	431,680	423,460	418,810
Aerospace [Member]
Segment Reporting Information [Line Items]
Net Sales	184,310	174,920	176,480
Operating Profit (Loss)	26,190	(90,810)	28,320
Capital Expenditures	3,370	3,950	5,010
Depreciation and Amortization	14,530	14,090	13,290
Assets	401,060	409,040	517,820
Energy [Member]
Segment Reporting Information [Line Items]
Net Sales	161,580	158,990	193,390
Operating Profit (Loss)	(5,410)	(13,840)	(97,160)
Capital Expenditures	3,090	2,800	7,610
Depreciation and Amortization	6,550	4,280	4,790
Assets	96,320	100,590	128,170
Engineered Components [Member]
Segment Reporting Information [Line Items]
Net Sales	127,280	118,770	159,840
Operating Profit (Loss)	15,740	15,300	18,240
Capital Expenditures	3,740	4,670	2,320
Depreciation and Amortization	3,980	4,090	4,200
Assets	76,520	78,570	88,320
Corporate [Member]
Segment Reporting Information [Line Items]
Operating Profit (Loss)	(28,410)	(32,490)	(32,120)
Capital Expenditures	9,460	30	50
Depreciation and Amortization	180	280	340
Assets	$ 27,620	$ 39,990	$ 17,180