Affiliated and Related Party Transactions (Schedule of Affiliated Transactions - Balance Sheet) (Parenthetical) (Detail) - USD ($) $ in Millions		Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Derivative assets with affiliates	[1]		$ 33	$ 51
Other Current Assets [Member]
Related Party Transaction [Line Items]
Derivative assets with affiliates		$ 4		8
Other Deferred Debits and Other Assets [Member]
Related Party Transaction [Line Items]
Derivative assets with affiliates		$ 29		$ 43

[1] Includes amounts recorded in other current assets of $4 million and $8 million as of September 30, 2023 and December 31, 2022, respectively, and amounts recorded in other deferred debits and other assets of $29 million and $43 million as of September 30, 2023 and December 31, 2022, respectively.