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
Balance, beginning of period (in shares) at Dec. 31, 2021		1,000,000
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	3
Net income	$ 531				531
Other comprehensive loss						2
Balance, end of period (in shares) at Mar. 31, 2022		1,000,000
Balance, end of period at Mar. 31, 2022	$ 9,951	$ 790	$ 6	8,532	685	(62)
Balance, end of period (in shares) at Mar. 31, 2022			629,000,000
Balance, beginning of period (in shares) at Dec. 31, 2022	800,000	1,000,000
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	(10)
Net income	$ 325				325
Other comprehensive loss						(1)
Balance, end of period (in shares) at Mar. 31, 2023	800,000	1,000,000
Balance, end of period at Mar. 31, 2023	$ 10,356	$ 790	$ 6	$ 8,558	$ 1,034	$ (32)
Balance, end of period (in shares) at Mar. 31, 2023	631,018,976		631,000,000