Commitments and Contingencies - Schedule of Long-term Commitments (Parenthetical) (Detail) $ in Millions	Dec. 31, 2023 USD ($)
Other Commitments [Line Items]
Total future minimum payments	$ 2,638
Fuel and Gas Supply [Member]
Other Commitments [Line Items]
Total future minimum payments	276
Transportation [Member]
Other Commitments [Line Items]
Total future minimum payments	$ 1,443