Derivatives - Summary Of Outstanding Notional Amounts (Details) BTU in Millions, $ in Millions		6 Months Ended	12 Months Ended
		Mar. 31, 2023 BTU	Sep. 30, 2022 MXN ($) BTU
Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Natural Gas Commodity Hedge [Member]
Derivative [Line Items]
Notional amount of natural gas derivatives | BTU		21.3	18.3
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member]
Derivative [Line Items]
Outstanding notional amounts | $	[1]		8,000.0

[1] At September 30, 2022, the outstanding foreign currency exchange contract was related to the purchase of 8.0 billion Mexican pesos ($389.9 million) for refinancing Grupo Gondi's external debt upon the Grupo Gondi Acquisition on December 1, 2022.