Pensions and Other Postretirement Benefit Plans (Schedule of Amounts Reclassified by Segment and Financial Statement) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Increase/(decrease) in expense Effect by segment operating expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Total operating expenses	$ 2,525	$ 2,356
Increase/(decrease) in expense Effect by segment operating expenses [Member] | Machine Clothing [Member]
Defined Benefit Plan Disclosure [Line Items]
Total operating expenses	(44)	24
Increase/(decrease) in expense Effect by segment operating expenses [Member] | Engineered Composites [Member]
Defined Benefit Plan Disclosure [Line Items]
Total operating expenses
Increase/(decrease) in expense Effect by segment operating expenses [Member] | Corporate Expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Total operating expenses	(2,481)	(2,380)
Increase/(decrease) in expense Effect by Statement of Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Total operating expenses	(2,525)	(2,356)
Increase/(decrease) in expense Effect by Statement of Income [Member] | Cost of goods sold [Member]
Defined Benefit Plan Disclosure [Line Items]
Total operating expenses	(503)	(716)
Increase/(decrease) in expense Effect by Statement of Income [Member] | Selling, general and administrative expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Total operating expenses	(2,022)	(1,754)
Increase/(decrease) in expense Effect by Statement of Income [Member] | Technical and research expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Total operating expenses		2
Increase/(decrease) in expense Effect by Statement of Income [Member] | Restructuring expenses, net [Member]
Defined Benefit Plan Disclosure [Line Items]
Total operating expenses		$ 112