CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (unaudited) - USD ($) $ in Millions	Total	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	Preferred Stock	Capital Surplus	Retained Earnings	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) Income	Treasury Stock
Balance at Dec. 31, 2020	$ 23,111							$ 2,051	$ 2,116	$ 3,635	$ 18,384							$ 2,601	$ (5,676)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,403										1,403
Other comprehensive income (loss), net of tax	(627)																	(627)
Cash dividends declared:
Common stock	(387)										(387)
Preferred stock		$ (15)	$ (15)	$ (5)	$ (6)	$ (8)	$ (6)					$ (15)	$ (15)	$ (5)	$ (6)	$ (8)	$ (6)
Shares acquired for treasury	(527)																		(527)
Impact of stock transactions under stock compensation plans, net	9									(33)									42
Other	(1)										(2)								1
Balance at Jun. 30, 2021	22,926							2,051	2,116	3,602	19,343							1,974	(6,160)
Balance at Mar. 31, 2021	22,595							2,051	2,116	3,592	18,863							1,792	(5,819)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	709										709
Other comprehensive income (loss), net of tax	182																	182
Cash dividends declared:
Common stock	(192)										(192)
Preferred stock		(15)	(7)	(3)	(3)	(4)	(3)					(15)	(7)	(3)	(3)	(4)	(3)
Shares acquired for treasury	(347)																		(347)
Impact of stock transactions under stock compensation plans, net	15									10									5
Other	(1)										(2)								1
Balance at Jun. 30, 2021	22,926							2,051	2,116	3,602	19,343							1,974	(6,160)
Balance at Dec. 31, 2021	22,210							2,051	2,116	3,624	20,236							1,207	(7,024)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,056										1,056
Other comprehensive income (loss), net of tax	(3,851)																	(3,851)
Cash dividends declared:
Common stock	(418)										(418)
Preferred stock		(15)	(15)	(6)	(6)	(8)	(6)					(15)	(15)	(6)	(6)	(8)	(6)
Impact of stock transactions under stock compensation plans, net	29									12									17
Balance at Jun. 30, 2022	18,970							2,051	2,116	3,636	20,818							(2,644)	(7,007)
Balance at Mar. 31, 2022	20,177							2,051	2,116	3,615	20,501							(1,096)	(7,010)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	562										562
Other comprehensive income (loss), net of tax	(1,548)																	(1,548)
Cash dividends declared:
Common stock	(209)										(209)
Preferred stock		$ (15)	$ (8)	$ (3)	$ (3)	$ (4)	$ (3)					$ (15)	$ (8)	$ (3)	$ (3)	$ (4)	$ (3)
Impact of stock transactions under stock compensation plans, net	24									21									3
Balance at Jun. 30, 2022	$ 18,970							$ 2,051	$ 2,116	$ 3,636	$ 20,818							$ (2,644)	$ (7,007)