Restructuring and Impairment Activities (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment expense	$ 400,000	$ 1,500,000	$ 1,400,000	$ 4,200,000
Restructuring Reserve [Roll Forward]
Balance at beginning of year			1,700,000	4,300,000	$ 4,300,000
Accruals for announced programs			1,100,000		3,500,000
Cash payments			(2,500,000)		(6,400,000)
Other			1,800,000		0
Exchange rate impacts			0		300,000
Balance at end of period	2,100,000		2,100,000		$ 1,700,000
Corporate, Non-Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment expense	0	(100,000)	0	100,000
Engineered Papers [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment expense	0	400,000	200,000	1,700,000
Engineered Papers [Member] | France [Member] | Employee severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment expense			200,000
Engineered Papers [Member] | France, Brazil, And United States [Member] | Employee severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment expense				900,000
Engineered Papers [Member] | Philippines [Member] | Asset Impairment Charge [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment expense			0	800,000
Advanced Materials & Structures Segment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment expense	$ 400,000	$ 1,200,000	1,200,000	$ 2,400,000
Advanced Materials & Structures Segment [Member] | UNITED STATES | Employee severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment expense			900,000
Advanced Materials & Structures Segment [Member] | UNITED STATES | Asset Impairment Charge [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and impairment expense			$ 300,000