Condensed Statements of Consolidated Changes in Equity (Unaudited) - USD ($) $ in Millions	Total	Cumulative Preferred Stock	Common Stock	Additional Paid-in-Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Series A Preferred Stock	Series A Preferred Stock Cumulative Preferred Stock
Balance, beginning of period (in shares) at Dec. 31, 2021		1,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of Series A Preferred Stock (in shares)								0
Redemption of Series A Preferred Stock								$ 0
Balance, beginning of period at Dec. 31, 2021		$ 790	$ 6	$ 8,529	$ 154	$ (64)
Balance, beginning of period (in shares) at Dec. 31, 2021			629,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans (in shares)			0
Issuances related to benefit and investment plans			$ 0	28
Net income	$ 923				923
Common Stock dividends declared (see Note 18)					(334)
Preferred Stock dividends declared (see Note 18)					(24)
Other comprehensive loss						(19)
Balance, end of period (in shares) at Sep. 30, 2022		1,000,000
Balance, end of period at Sep. 30, 2022	9,989	$ 790	$ 6	8,557	719	(83)
Balance, end of period (in shares) at Sep. 30, 2022			629,000,000
Balance, beginning of period (in shares) at Jun. 30, 2022		1,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of Series A Preferred Stock (in shares)								0
Redemption of Series A Preferred Stock								$ 0
Balance, beginning of period at Jun. 30, 2022		$ 790	$ 6	8,544	768	(85)
Balance, beginning of period (in shares) at Jun. 30, 2022			629,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans (in shares)			0
Issuances related to benefit and investment plans			$ 0	13
Net income	202				202
Common Stock dividends declared (see Note 18)					(227)
Preferred Stock dividends declared (see Note 18)					(24)
Other comprehensive loss						2
Balance, end of period (in shares) at Sep. 30, 2022		1,000,000
Balance, end of period at Sep. 30, 2022	$ 9,989	$ 790	$ 6	8,557	719	(83)
Balance, end of period (in shares) at Sep. 30, 2022			629,000,000
Balance, beginning of period (in shares) at Dec. 31, 2022	800,000	1,000,000					800,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of Series A Preferred Stock (in shares)								(1,000,000)
Redemption of Series A Preferred Stock								$ (790)
Balance, beginning of period at Dec. 31, 2022	$ 10,042	$ 790	$ 6	8,568	709	(31)
Balance, beginning of period (in shares) at Dec. 31, 2022	629,535,631		630,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans (in shares)			1,000,000
Issuances related to benefit and investment plans			$ 0	13
Net income	$ 725				725
Common Stock dividends declared (see Note 18)					(366)
Preferred Stock dividends declared (see Note 18)					(41)
Other comprehensive loss						2
Balance, end of period (in shares) at Sep. 30, 2023	0	0					0
Balance, end of period at Sep. 30, 2023	$ 9,585	$ 0	$ 6	8,581	1,027	(29)
Balance, end of period (in shares) at Sep. 30, 2023	631,209,962		631,000,000
Balance, beginning of period (in shares) at Jun. 30, 2023		1,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of Series A Preferred Stock (in shares)								(1,000,000)
Redemption of Series A Preferred Stock								$ (790)
Balance, beginning of period at Jun. 30, 2023		$ 790	$ 6	8,570	1,032	(32)
Balance, beginning of period (in shares) at Jun. 30, 2023			631,000,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuances related to benefit and investment plans (in shares)			0
Issuances related to benefit and investment plans			$ 0	11
Net income	$ 282				282
Common Stock dividends declared (see Note 18)					(246)
Preferred Stock dividends declared (see Note 18)					(41)
Other comprehensive loss						3
Balance, end of period (in shares) at Sep. 30, 2023	0	0					0
Balance, end of period at Sep. 30, 2023	$ 9,585	$ 0	$ 6	$ 8,581	$ 1,027	$ (29)
Balance, end of period (in shares) at Sep. 30, 2023	631,209,962		631,000,000