Restructuring - Actual and Estimated Pre-Tax Expenses (Details) - Technical Nonwovens - USD ($) $ in Thousands	3 Months Ended		12 Months Ended	18 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2019	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Total estimated expenses					$ 4,200
Total pre-tax expense incurred	$ 97	$ 376	$ 2,959	$ 3,432
Estimated remaining expense	768		1,241	768
Severance and Related Expenses
Restructuring Cost and Reserve [Line Items]
Total estimated expenses					1,250
Total pre-tax expense incurred	53	16	787	856
Estimated remaining expense	394		463	394
Contract Termination Expenses
Restructuring Cost and Reserve [Line Items]
Total estimated expenses					450
Total pre-tax expense incurred	0	0	290	290
Estimated remaining expense	160		160	160
Facility Exit, Move and Set-up Expenses
Restructuring Cost and Reserve [Line Items]
Total estimated expenses					$ 2,500
Total pre-tax expense incurred	44	$ 360	1,882	2,286
Estimated remaining expense	$ 214		$ 618	$ 214