Derivatives - Summary Of Outstanding Notional Amounts (Details) - BTU BTU in Millions	Dec. 31, 2023	Sep. 30, 2023
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Natural Gas Commodity Hedge [Member]
Derivative [Line Items]
Notional amount of natural gas derivatives	20.4	22.0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-5

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration