Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Segment Reporting Information [Line Items]
Net sales	$ 170,920	$ 188,410	$ 190,830	$ 173,370	$ 170,090	$ 182,100	$ 181,690	$ 171,150	$ 723,530	$ 705,030		$ 656,160
Operating Profit									91,220	108,810		92,720
Capital Expenditures									29,670	23,420		33,710
Depreciation and Amortization									43,500	40,490		40,310
Assets	1,192,700				1,100,520				1,192,700	1,100,520		1,033,200
Packaging [Member]
Segment Reporting Information [Line Items]
Net sales									392,340	368,200		344,570
Operating Profit									80,770	84,590		80,610
Capital Expenditures									16,400	13,590		17,140
Depreciation and Amortization									24,650	21,620		21,630
Assets	546,950				435,140				546,950	435,140		431,680
Aerospace [Member]
Segment Reporting Information [Line Items]
Net sales									164,840	156,380		154,050
Operating Profit									28,400	24,930		24,960
Capital Expenditures									6,280	820		2,800
Depreciation and Amortization									13,700	13,900		13,290
Assets	354,500				357,640				354,500	357,640		365,120
Specialty Products [Member]
Segment Reporting Information [Line Items]
Net sales									166,350	180,450		157,540
Operating Profit									16,550	23,350		17,280
Capital Expenditures									6,920	4,120		4,310
Depreciation and Amortization									4,870	4,690		5,210
Assets	116,010				117,110				116,010	117,110		112,460
Corporate [Member]
Segment Reporting Information [Line Items]
Operating Profit									(34,500)	(24,060)		(30,130)
Capital Expenditures									70	4,890	[1]	9,460	[1]
Depreciation and Amortization									280	280		180
Assets	175,240				95,260				175,240	95,260		31,860
Continuing Operations [Member]
Segment Reporting Information [Line Items]
Assets	1,192,700				1,005,150				1,192,700	1,005,150		941,120
Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Assets	$ 0				$ 95,370				$ 0	$ 95,370		$ 92,080

[1] ^(a) Corporate capital expenditures for the years ended December 31, 2018 and 2017, respectively, are primarily related to purchases of machinery and equipment formerly held under operating leases. These purchased assets were subsequently transferred from Corporate to the reportable segment utilizing the assets.