Restructuring - Accrued Restructuring Costs (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Cash paid	$ (100)	$ (700)
Technical Nonwovens
Restructuring Reserve [Roll Forward]
Balance		147
Pre-tax restructuring expenses, excluding depreciation		591
Cash paid		(661)	$ (4,200)
Balance	$ 77	$ 77