Regulatory Matters - PAC - Regulatory Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Sep. 01, 2023
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 7,033	$ 6,818
Regulatory liabilities, noncurrent	$ 6,754	6,644
Cost of removal
Regulatory Liabilities [Line Items]
Regulatory liability, amortization period	27 years
Total regulatory liabilities	$ 2,918	2,741
Deferred income taxes
Regulatory Liabilities [Line Items]
Total regulatory liabilities	2,493	2,733	$ 24
PAC
Regulatory Liabilities [Line Items]
Total regulatory liabilities	2,642	2,610
Regulatory liabilities, current	92	70
Regulatory liabilities, noncurrent	$ 2,550	2,540
PAC | Cost of removal
Regulatory Liabilities [Line Items]
Regulatory liability, amortization period	26 years
Total regulatory liabilities	$ 1,560	1,456
PAC | Deferred income taxes
Regulatory Liabilities [Line Items]
Total regulatory liabilities	861	1,006
PAC | Other
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 221	$ 148