Restructuring (Narrative) (Details) - USD ($) $ in Thousands	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 expense			$ 9,000
Accrued restructuring costs expected to be paid within one year	$ 6,100		6,100
Accrued restructuring costs expected to be paid in year two	300		300
Severance and outplacement costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense			10,100
Write-off of intangible assets and equipment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense		$ 4,500
Cost of goods sold for write-off of inventory [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense		$ 3,200
Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	200
AEC assets [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 1,700		$ 6,100	$ 6,100
Machine Clothing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring expense					$ 1,100