Reportable Segment Data (Schedule of Operating Data) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Segment Reporting Information [Line Items]
Net sales	$ 194,589	$ 200,252	$ 566,606	$ 589,887
Operating income/(loss)	23,112	26,758	(63,801)	64,312
Interest expense, net	3,997	4,377	12,610	13,939
Other expense/(income), net	3,069	(9)	5,062	4,811
Income/(loss) before income taxes	16,046	22,390	(81,473)	45,562
Machine Clothing [Member]
Segment Reporting Information [Line Items]
Net sales	177,471	188,334	518,881	55,993
Operating income/(loss)	44,918	48,867	120,760	136,847
Engineered Composites [Member]
Segment Reporting Information [Line Items]
Net sales	17,118	11,918	47,725	33,894
Operating income/(loss)	(312)	(1,434)	(653)	(3,621)
Research Expense [Member]
Segment Reporting Information [Line Items]
Operating income/(loss)	(6,734)	(6,400)	(20,052)	(20,777)
Unallocated Expenses [Member]
Segment Reporting Information [Line Items]
Operating income/(loss)	$ (14,760)	$ (14,275)	$ (163,856)	$ (48,137)