CONSOLIDATED STATEMENT OF EQUITY (UNAUDITED) - USD ($) shares in Millions, $ in Millions	Total	Subsidiaries	Common Stock	Common Stock Subsidiaries	Additional Paid-In Capital	Retained Earnings	Retained Earnings Subsidiaries	Treasury Stock	Capital Stock Expense	Accumulated Other Comprehensive Income/(Loss)	Accumulated Other Comprehensive Income/(Loss) Subsidiaries	Non- controlling Interest
Beginning balance (shares) at Dec. 31, 2020			342	235
Beginning balance at Dec. 31, 2020	$ 19,065		$ 36		$ 8,808	$ 11,178		$ (1,038)	$ (112)	$ (25)		$ 218
Beginning balance (shares) at Dec. 31, 2020								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	420					419						1
Common stock dividends	(265)	$ (247)				(265)	$ (247)
Issuance of common shares for stock plans	28				28
Other comprehensive income	4									4
Distributions to noncontrolling interest	(3)											(3)
Net proceeds from sale of equity interest	33											33
Ending balance (shares) at Mar. 31, 2021			342	235
Ending balance at Mar. 31, 2021	$ 19,282		$ 36		8,836	11,332		$ (1,038)	(112)	(21)		249
Ending balance (shares) at Mar. 31, 2021								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends per share (dollars per share)	$ 0.775
Beginning balance (shares) at Dec. 31, 2020			342	235
Beginning balance at Dec. 31, 2020	$ 19,065		$ 36		8,808	11,178		$ (1,038)	(112)	(25)		218
Beginning balance (shares) at Dec. 31, 2020								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,007
Other comprehensive income	8
Ending balance (shares) at Sep. 30, 2021			354	235
Ending balance at Sep. 30, 2021	20,377		$ 37		9,683	11,495		$ (1,038)	(123)	(17)		340
Ending balance (shares) at Sep. 30, 2021								23
Beginning balance (shares) at Mar. 31, 2021			342	235
Beginning balance at Mar. 31, 2021	19,282		$ 36		8,836	11,332		$ (1,038)	(112)	(21)		249
Beginning balance (shares) at Mar. 31, 2021								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	118					165						(47)
Common stock dividends	(266)	(247)				(266)	(247)
Issuance of common shares – public offering (shares)			11
Issuance of common shares - public offering	775		$ 1		785				(11)
Issuance of common shares for stock plans	34				34
Other comprehensive income	2									2
Distributions to noncontrolling interest	(4)											(4)
Net proceeds from sale of equity interest	112											112
Ending balance (shares) at Jun. 30, 2021			353	235
Ending balance at Jun. 30, 2021	$ 20,053		$ 37		9,655	11,231		$ (1,038)	(123)	(19)		310
Ending balance (shares) at Jun. 30, 2021								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends per share (dollars per share)	$ 0.775
Net income	$ 469					538						(69)
Common stock dividends	(274)	(247)				(274)	(247)
Issuance of common shares – public offering (shares)			1
Issuance of common shares - public offering	0
Issuance of common shares for stock plans	28				28
Other comprehensive income	2									2
Distributions to noncontrolling interest	(8)											(8)
Net proceeds from sale of equity interest	107											107
Ending balance (shares) at Sep. 30, 2021			354	235
Ending balance at Sep. 30, 2021	$ 20,377		$ 37		9,683	11,495		$ (1,038)	(123)	(17)		340
Ending balance (shares) at Sep. 30, 2021								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends per share (dollars per share)	$ 0.775
Beginning balance (shares) at Dec. 31, 2021			354	235
Beginning balance at Dec. 31, 2021	$ 20,336		$ 37		9,710	11,445		$ (1,038)	(122)	5		299
Beginning balance (shares) at Dec. 31, 2021								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	554					602						(48)
Common stock dividends	(280)	(245)				(280)	(245)
Issuance of common shares - public offering	1								1
Issuance of common shares for stock plans	18				18
Other comprehensive income		1									$ 1
Distributions to noncontrolling interest	(6)											(6)
Ending balance (shares) at Mar. 31, 2022			354	235
Ending balance at Mar. 31, 2022	$ 20,623		$ 37		9,728	11,767		$ (1,038)	(121)	5		245
Ending balance (shares) at Mar. 31, 2022								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends per share (dollars per share)	$ 0.79
Beginning balance (shares) at Dec. 31, 2021			354	235
Beginning balance at Dec. 31, 2021	$ 20,336		$ 37		9,710	11,445		$ (1,038)	(122)	5		299
Beginning balance (shares) at Dec. 31, 2021								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,427
Other comprehensive income	6
Ending balance (shares) at Sep. 30, 2022			355	235
Ending balance at Sep. 30, 2022	20,976		$ 37		9,784	12,075		$ (1,038)	(121)	11		228
Ending balance (shares) at Sep. 30, 2022								23
Beginning balance (shares) at Mar. 31, 2022			354	235
Beginning balance at Mar. 31, 2022	20,623		$ 37		9,728	11,767		$ (1,038)	(121)	5		245
Beginning balance (shares) at Mar. 31, 2022								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	254					255						(1)
Common stock dividends	(280)	(245)				(280)	(245)
Issuance of common shares for stock plans	29				29
Other comprehensive income	5									5
Distributions to noncontrolling interest	(10)											(10)
Ending balance (shares) at Jun. 30, 2022			354	235
Ending balance at Jun. 30, 2022	$ 20,621		$ 37		9,757	11,742		$ (1,038)	(121)	10		234
Ending balance (shares) at Jun. 30, 2022								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends per share (dollars per share)	$ 0.79
Net income	$ 619					613						6
Common stock dividends	(280)	$ (244)				(280)	$ (244)
Issuance of common shares – public offering (shares)			1
Issuance of common shares - public offering	0
Issuance of common shares for stock plans	27				27
Other comprehensive income	1									1
Distributions to noncontrolling interest	(12)											(12)
Ending balance (shares) at Sep. 30, 2022			355	235
Ending balance at Sep. 30, 2022	$ 20,976		$ 37		$ 9,784	$ 12,075		$ (1,038)	$ (121)	$ 11		$ 228
Ending balance (shares) at Sep. 30, 2022								23
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends per share (dollars per share)	$ 0.79