Financial Risk Management Activities - Fair Value Measurements - Additional Information (Detail) $ in Millions	Sep. 30, 2023 USD ($)
Fair Value Disclosures [Abstract]
Long-term debt	$ 8,548
Long-term debt, fair value	$ 8,242

Amount, after deduction of 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