Long-Term PPAs - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2019 MW
Long Term Contract For Purchase Of Electric Power [Line Items]
Purchased power	$ 105	$ 78	$ 151
Power Purchase Agreements [Member] | Variable Interest Entity Not Primary Beneficiary [Member]
Long Term Contract For Purchase Of Electric Power [Line Items]
Purchased power	$ 34	$ 35	$ 70
Maximum [Member]
Long Term Contract For Purchase Of Electric Power [Line Items]
PPAs range | MW				515