Restructuring - Accrued Restructuring Costs (Details) - Technical Nonwovens - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring expenses, excluding depreciation	$ 2,012	$ 510
Cash paid	(2,198)	(177)
Restructuring reserve	$ 147	$ 333