Non-Derivative Fair Value Measurements (Details) - USD ($) $ in Millions		9 Months Ended		12 Months Ended
		Sep. 30, 2023		Dec. 31, 2022
Nuclear decommissinoning fund [Abstract]
Equity investments in unconsolidated subsidiaries		$ 244		$ 219
Miscellaneous investments		135		133
Debt Securities, Available-for-sale, Unrealized Gain		1,100		1,000
Debt Securities, Available-for-sale, Unrealized Loss		86		90
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Due in one year or less		10
Due in 1 to 5 years		236
Due in 5 to 10 years		257
Due after 10 years		223
Total		726
Debt Securities, Available-for-Sale, Unrealized Loss Position [Line Items]
Debt Securities, Available-for-sale, Unrealized Gain		1,100		1,000
Debt Securities, Available-for-sale, Unrealized Loss		86		90
Interest Rate Swap
Nuclear decommissinoning fund [Abstract]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net		1
Fair Value Measured on a Recurring Basis | Cost
Nuclear decommissinoning fund [Abstract]
Decommissioning Fund Investments		2,049	[1]	1,976	[2]
Fair Value Measured on a Recurring Basis | Cost | Cash equivalents
Nuclear decommissinoning fund [Abstract]
Cash equivalents		27	[1]	29	[2]
Fair Value Measured on a Recurring Basis | Cost | Commingled funds
Nuclear decommissinoning fund [Abstract]
Alternative investment	[2]			803
Investments, Fair Value Disclosure	[1]	731
Fair Value Measured on a Recurring Basis | Cost | Debt securities
Nuclear decommissinoning fund [Abstract]
Debt securities		782	[1]	738	[2]
Fair Value Measured on a Recurring Basis | Cost | Equity securities
Nuclear decommissinoning fund [Abstract]
Equity Securities, FV-NI		509	[1]	406	[2]
Fair Value Measured on a Recurring Basis | Fair Value
Nuclear decommissinoning fund [Abstract]
Alternative investment		1,059	[1]	1,178	[2]
Decommissioning Fund Investments		3,014	[1]	2,882	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Cash equivalents
Nuclear decommissinoning fund [Abstract]
Cash equivalents		27	[1]	29	[2]
Alternative investment		0	[1]	0	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Commingled funds
Nuclear decommissinoning fund [Abstract]
Alternative investment		1,059	[1]	1,178	[2]
Investments, Fair Value Disclosure		1,059
Fair Value Measured on a Recurring Basis | Fair Value | Debt securities
Nuclear decommissinoning fund [Abstract]
Debt securities		726	[1]	675	[2]
Alternative investment		0	[1]	0	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Equity securities
Nuclear decommissinoning fund [Abstract]
Equity Securities, FV-NI		1,202	[1]	1,000	[2]
Alternative investment		0	[1]	0	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1
Nuclear decommissinoning fund [Abstract]
Decommissioning Fund Investments		1,227	[1]	1,028	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Cash equivalents
Nuclear decommissinoning fund [Abstract]
Cash equivalents		27	[1]	29	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Commingled funds
Nuclear decommissinoning fund [Abstract]
Alternative investment	[2]			0
Investments, Fair Value Disclosure	[1]	0
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Debt securities
Nuclear decommissinoning fund [Abstract]
Debt securities		0	[1]	0	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 1 | Equity securities
Nuclear decommissinoning fund [Abstract]
Equity Securities, FV-NI		1,200	[1]	999	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2
Nuclear decommissinoning fund [Abstract]
Decommissioning Fund Investments		721	[1]	670	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Cash equivalents
Nuclear decommissinoning fund [Abstract]
Cash equivalents		0	[1]	0	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Commingled funds
Nuclear decommissinoning fund [Abstract]
Alternative investment	[2]			0
Investments, Fair Value Disclosure	[1]	0
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Debt securities
Nuclear decommissinoning fund [Abstract]
Debt securities		719	[1]	669	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 2 | Equity securities
Nuclear decommissinoning fund [Abstract]
Equity Securities, FV-NI		2	[1]	1	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3
Nuclear decommissinoning fund [Abstract]
Decommissioning Fund Investments		7	[1]	6	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Cash equivalents
Nuclear decommissinoning fund [Abstract]
Cash equivalents		0	[1]	0	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Commingled funds
Nuclear decommissinoning fund [Abstract]
Alternative investment	[2]			0
Investments, Fair Value Disclosure	[1]	0
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Debt securities
Nuclear decommissinoning fund [Abstract]
Debt securities		7	[1]	6	[2]
Fair Value Measured on a Recurring Basis | Fair Value | Level 3 | Equity securities
Nuclear decommissinoning fund [Abstract]
Equity Securities, FV-NI		$ 0	[1]	$ 0	[2]

[1] Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $244 million of equity method investments and $135 million of rabbi trust assets and other miscellaneous investments.

[2] Reported in nuclear decommissioning fund and other investments on the consolidated balance sheets, which also includes $219 million of equity investments in unconsolidated subsidiaries and $133 million of rabbi trust assets and other miscellaneous investments.