Restructuring - Narrative (Details) - Technical Nonwovens - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Apr. 30, 2017
Restructuring Cost and Reserve [Line Items]
Estimated pre-tax restructuring expense		$ 5,000
Restructuring, expected costs resulting in future cash expenditures					$ 4,800
Cash paid		320	$ 3,500
Pre-tax restructuring expenses, excluding depreciation		400
Selling, Product Development and Administrative Expenses
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring expenses, excluding depreciation		500
Cost of Sales
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring expenses, excluding depreciation		$ 100
Forecast
Restructuring Cost and Reserve [Line Items]
Pre-tax restructuring expenses, excluding depreciation	$ 1,500			$ 3,500