Financial Instruments (Long-Term Debt) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Financial Instruments, Owned, at Fair Value, by Type, Alternative [Abstract]
Carrying Amount	$ 2,085,235	$ 2,632,409
Fair Value	$ 1,951,250	$ 2,453,209

Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant