Fair Value Measurements - Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Debt Securities
Liabilities:
Debt, weighted average interest rate	3.99%	3.19%
Decommissioning fund investments, debt securities, average maturity	7 years	11 years
Decommissioning fund investments, debt maturities, one through five years, fair value	$ 1,045
Decommissioning fund investments, debt maturities, five through ten years, fair value	599
Decommissioning fund investments, debt maturities, after ten years, fair value	415
Fair Value, Recurring
Assets:
Sub-total	5	$ 14
Liabilities:
Total liabilities	5	14
Fair Value, Recurring | Equity Securities
Assets:
Assets measured at net asset value	821	579
Fair Value, Recurring | Commodity contract
Assets:
Assets	5	14
Liabilities:
Derivative liabilities	5	14
Fair Value, Recurring | Interest Rate Swaps
Assets:
Assets	0	0
Liabilities:
Derivative liabilities	0	0
Fair Value, Recurring | Total
Assets:
Sub-total	6,946	5,594
Total assets	7,767	6,173
Liabilities:
Total liabilities	4,718	6,946
Fair Value, Recurring | Total | Equity Securities
Assets:
Nuclear decommissioning trust	1,560	638
Fair Value, Recurring | Total | Debt Securities
Assets:
Nuclear decommissioning trust	2,059	734
Fair Value, Recurring | Total | Commodity contract
Assets:
Assets	3,231	4,158
Liabilities:
Derivative liabilities	4,691	6,898
Fair Value, Recurring | Total | Interest Rate Swaps
Assets:
Assets	96	64
Liabilities:
Derivative liabilities	27	48
Level 1 | Fair Value, Recurring
Assets:
Sub-total	3,566	3,524
Liabilities:
Total liabilities	2,118	3,815
Level 1 | Fair Value, Recurring | Equity Securities
Assets:
Nuclear decommissioning trust	1,560	638
Level 1 | Fair Value, Recurring | Debt Securities
Assets:
Nuclear decommissioning trust	83	0
Level 1 | Fair Value, Recurring | Commodity contract
Assets:
Assets	1,923	2,886
Liabilities:
Derivative liabilities	2,118	3,815
Level 1 | Fair Value, Recurring | Interest Rate Swaps
Assets:
Assets	0	0
Liabilities:
Derivative liabilities	0	0
Level 2 | Fair Value, Recurring
Assets:
Sub-total	2,534	1,426
Liabilities:
Total liabilities	1,002	1,443
Level 2 | Fair Value, Recurring | Equity Securities
Assets:
Nuclear decommissioning trust	0	0
Level 2 | Fair Value, Recurring | Debt Securities
Assets:
Nuclear decommissioning trust	1,976	734
Level 2 | Fair Value, Recurring | Commodity contract
Assets:
Assets	462	628
Liabilities:
Derivative liabilities	975	1,395
Level 2 | Fair Value, Recurring | Interest Rate Swaps
Assets:
Assets	96	64
Liabilities:
Derivative liabilities	27	48
Level 3
Assets:
Assets	841	630
Liabilities:
Derivative liabilities	1,593	1,674
Level 3 | Fair Value, Recurring
Assets:
Sub-total	841	630
Liabilities:
Total liabilities	1,593	1,674
Level 3 | Fair Value, Recurring | Equity Securities
Assets:
Nuclear decommissioning trust	0	0
Level 3 | Fair Value, Recurring | Debt Securities
Assets:
Nuclear decommissioning trust	0	0
Level 3 | Fair Value, Recurring | Commodity contract
Assets:
Assets	841	630
Liabilities:
Derivative liabilities	1,593	1,674
Level 3 | Fair Value, Recurring | Interest Rate Swaps
Assets:
Assets	0	0
Liabilities:
Derivative liabilities	$ 0	$ 0