Reportable Segments and Geographic Data (Schedule of Operating Assets and Capital Expenditures by Reporting Segment) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 1,166,888	$ 1,156,697	$ 1,230,928
Capital expenditures and purchased software	64,457	37,207	27,428
Cash	222,666	190,718	118,909	117,925
Machine Clothing [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	624,388	660,595	713,142
Capital expenditures and purchased software	14,881	14,717	11,141
Engineered Composites [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	147,104	109,717	80,916
Capital expenditures and purchased software	36,928	18,979	9,684
Significant Reconciling Items [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Cash	222,666	190,718	118,909
Income taxes receivable and deferred	133,485	144,480	164,654
Other assets	39,245	51,187	34,670
Assets of discontinued operations			118,637
Research Expense [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Capital expenditures and purchased software	8,011	1,493	2,052
Unallocated Expenses [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Capital expenditures and purchased software	$ 4,637	$ 2,018	$ 4,551