CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (unaudited) - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment		Cumulative Effect, Period of Adoption, Adjusted Balance	Series H Preferred Stock	Series I Preferred Stock	Series J Preferred Stock	Series K Preferred Stock	Series L Preferred Stock	Class B, Series A Preferred Stock	Common Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred Stock	Preferred Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Capital Surplus	Capital Surplus Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment		Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings Series H Preferred Stock	Retained Earnings Series I Preferred Stock	Retained Earnings Series J Preferred Stock	Retained Earnings Series K Preferred Stock	Retained Earnings Series L Preferred Stock	Retained Earnings Class B, Series A Preferred Stock	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock	Treasury Stock Cumulative Effect, Period of Adoption, Adjusted Balance
Beginning balance at Dec. 31, 2022	$ 17,327	$ 37		$ 17,364							$ 2,051	$ 2,051	$ 2,116	$ 2,116	$ 3,684	$ 3,684	$ 21,689	$ 37		$ 21,726							$ (5,110)	$ (5,110)	$ (7,103)	$ (7,103)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,819																1,819
Other comprehensive loss, net of tax	(1,729)																										(1,729)
Cash dividends declared:
Common stock	(698)																(698)
Preferred stock					$ (29)	$ (22)	$ (19)	$ (9)	$ (12)	$ (9)											$ (29)	$ (22)	$ (19)	$ (9)	$ (12)	$ (9)
Shares acquired for treasury	(201)																												(201)
Impact of stock transactions under stock compensation plans, net	89														49														40
Ending balance at Sep. 30, 2023	16,544										2,051		2,116		3,733		22,747										(6,839)		(7,264)
Beginning balance at Dec. 31, 2022	17,327	37		17,364							2,051	2,051	2,116	2,116	3,684	3,684	21,689	37		21,726							(5,110)	(5,110)	(7,103)	(7,103)
Ending balance at Dec. 31, 2023	$ 19,172	(10)	[1]	19,162							2,051	2,051	2,116	2,116	3,757	3,757	22,997	(10)	[1]	22,987							(4,487)	(4,487)	(7,262)	(7,262)
Cash dividends declared:
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2023-02 [Member]
Beginning balance at Jun. 30, 2023	$ 17,809										2,051		2,116		3,708		22,366										(5,166)		(7,266)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	660																660
Other comprehensive loss, net of tax	(1,673)																										(1,673)
Cash dividends declared:
Common stock	(242)																(242)
Preferred stock					(13)	(7)	(7)	(3)	(4)	(3)											(13)	(7)	(7)	(3)	(4)	(3)
Impact of stock transactions under stock compensation plans, net	27														25														2
Ending balance at Sep. 30, 2023	16,544										2,051		2,116		3,733		22,747										(6,839)		(7,264)
Beginning balance at Dec. 31, 2023	19,172	$ (10)	[1]	$ 19,162							2,051	$ 2,051	2,116	$ 2,116	3,757	$ 3,757	22,997	$ (10)	[1]	$ 22,987							(4,487)	$ (4,487)	(7,262)	$ (7,262)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,694																1,694
Other comprehensive loss, net of tax	1,041																										1,041
Cash dividends declared:
Common stock	(740)																(740)
Preferred stock					(39)	(32)	(20)	(9)	(12)	(9)											(39)	(32)	(20)	(9)	(12)	(9)
Shares acquired for treasury	(327)																												(327)
Impact of stock transactions under stock compensation plans, net	75														27														48
Ending balance at Sep. 30, 2024	20,784										2,051		2,116		3,784		23,820										(3,446)		(7,541)
Beginning balance at Jun. 30, 2024	19,226										2,051		2,116		3,764		23,542										(4,901)		(7,346)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	573																573
Other comprehensive loss, net of tax	1,455																										1,455
Cash dividends declared:
Common stock	(254)																(254)
Preferred stock					$ (13)	$ (11)	$ (7)	$ (3)	$ (4)	$ (3)											$ (13)	$ (11)	$ (7)	$ (3)	$ (4)	$ (3)
Shares acquired for treasury	(202)																												(202)
Impact of stock transactions under stock compensation plans, net	27														20														7
Ending balance at Sep. 30, 2024	$ 20,784										$ 2,051		$ 2,116		$ 3,784		$ 23,820										$ (3,446)		$ (7,541)

[1] Related to the adoption of ASU 2023-02 as of January 1, 2024. Refer to Note 3 for additional information.