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Summary of Significant Accounting Policies (Narrative) (Details) - USD ($)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Asset Retirement Obligation	$ 4,800,000	$ 4,200,000
Exposure to Workers Compensation Claims, Per Incident	800,000
Workers' Compensation Liability	10,400,000	10,400,000
Debt Issuance Costs, Net	$ 3,500,000
Income Tax Benefit, Likelihood of Realization Threshold	50.00%
Realized Gain (Loss), Foreign Currency Transaction, before Tax	$ (9,500,000)	(2,200,000)	$ (3,300,000)
Minimum [Member]
Finite-Lived Tangible Asset, Useful Life, Maximum	3 years
Maximum
Finite-Lived Tangible Asset, Useful Life, Maximum	10 years
Land Improvements [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life, Minimum	10 years
Land Improvements [Member] | Maximum
Property, Plant and Equipment, Useful Life, Minimum	20 years
Building [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life, Minimum	10 years
Building [Member] | Maximum
Property, Plant and Equipment, Useful Life, Minimum	40 years
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment, Useful Life, Minimum	3 years
Machinery and Equipment [Member] | Maximum
Property, Plant and Equipment, Useful Life, Minimum	20 years
Capitalized internal-use software: | Maximum
Property, Plant and Equipment, Useful Life, Minimum	6 years
U.S. Pipe [Member] | Maximum
Discontinued Operations, Receivable from Buyer of Discontinued Operation	$ 6,900,000	6,500,000
Unsecured Debt [Member]
Debt Issuance Costs, Net	2,500,000	$ 3,200,000
Revolving Credit Facility [Member]
Debt Issuance Costs, Net	900,000
Debt
Debt Issuance Costs, Net	$ 100,000

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