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Number of New Production Lines

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Basis of Financial Statement Presentation - Narrative (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Dec. 31, 2019 USD ($) arrangement	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2020 production_line	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Number of new production lines \| production_line				2
Net cash provided by operating activities					$ 74,613	$ 62,964
Social cost reimbursements related to COVID-19					2,000
Limit on monthly payments for production of medical supplies, COVID-19					13,500
Cash on hand	$ 51,331	$ 122,043			122,043		$ 51,331
Number of arrangements to sell accounts receivable \| arrangement	2
Proportion of trade receivables in cash at time of sale (as a percent)	90.00%
Proportion of trade receivables in cash when customer pays (as a percent)	10.00%
Trade receivables sold during period		21,300			64,300
Cash received for trade receivables sold		59,100			59,100
Fees related to trade receivables sold		200
Comprehensive (loss) income		$ (5,477)	$ (5,849)		$ (72,474)	10,773
Maximum
Debt Instrument [Line Items]
Proportion of investment in facility funded by French government (as a percent)		30.00%			30.00%
Revision of Prior Period, Adjustment
Debt Instrument [Line Items]
Comprehensive (loss) income			$ 19,000			$ 19,000	$ 19,000
Performance Materials
Debt Instrument [Line Items]
Increase (decrease) in revenue (as a percent)				(4.60%)
Performance Materials \| Filtration
Debt Instrument [Line Items]
Increase (decrease) in revenue (as a percent)		37.80%
Performance Materials \| Sealing and Advanced Solutions
Debt Instrument [Line Items]
Increase (decrease) in revenue (as a percent)		(1.70%)
Technical Nonwovens
Debt Instrument [Line Items]
Increase (decrease) in revenue (as a percent)		12.50%		(18.80%)	(8.50%)
Technical Nonwovens \| Industrial Filtration
Debt Instrument [Line Items]
Increase (decrease) in revenue (as a percent)		(10.00%)
Technical Nonwovens \| Advanced Materials
Debt Instrument [Line Items]
Increase (decrease) in revenue (as a percent)		(6.80%)
Thermal Acoustical Solutions
Debt Instrument [Line Items]
Increase (decrease) in revenue (as a percent)		(0.80%)		(35.40%)
Revolving Credit Facility \| Amended Credit Facility
Debt Instrument [Line Items]
Draw on credit facility					$ 20,000