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, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 1,156,697	$ 1,230,928	$ 1,278,293
Capital expenditures and purchased software	37,207	27,428	30,957
Machine Clothing [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	660,595	713,142	773,135
Capital expenditures and purchased software	14,717	11,141	19,234
Engineered Composites [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	109,717	80,916	74,332
Capital expenditures and purchased software	18,979	9,684	6,559
Cash [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	190,718	118,909	117,925
Income Taxes Receivable and Deferred [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	144,480	164,654	179,535
Other Assets [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	51,187	34,670	30,771
Assets of Discontinued Operations [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets		118,637	102,595
Research Expense [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Capital expenditures and purchased software	1,493	2,052	1,084
Unallocated Expenses [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Capital expenditures and purchased software	$ 2,018	$ 4,551	$ 4,080