Litigation and Related Matters (Narrative) (Details) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended	48 Months Ended
	Sep. 30, 2010 Site	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Sep. 30, 2024 USD ($) Site	Sep. 30, 2023 USD ($)	Dec. 31, 2007	Dec. 31, 2021 USD ($)	Dec. 31, 2023 USD ($)
Loss Contingencies [Line Items]
Settlement agreement amount of litigation agreement								$ 53.0
Environmental insurance recoveries received in excess of cumulative expenses incurred									$ 2.6
Estimated cost for non-groundwater elements				$ 8.0
Reserves for potential environmental liabilities		$ 0.1	$ 0.5		$ 4.1	$ 0.5
Macon Site [Member]
Loss Contingencies [Line Items]
Number of landfills listed as Superfund site | Site					2
Number of landfills AWI entered into an Administrative Order on Consent for a Removal Action | Site	1
Submission date of final report to EPA	Oct. 31, 2016
Elizabeth City [Member]
Loss Contingencies [Line Items]
Percentage of site costs Navy agreed to pay							33.33%
Cost of goods sold [Member]
Loss Contingencies [Line Items]
Reserves for potential environmental liabilities		2.5	$ 0.5		$ 2.5	$ 0.5
SG&A Expenses [Member]
Loss Contingencies [Line Items]
Reserves for potential environmental liabilities		1.6			1.6
Other Long-Term Liabilities [Member]
Loss Contingencies [Line Items]
Environmental liabilities		$ 4.2			$ 4.2				$ 0.5