Consolidated Statement of Changes in Shareholders' Equity - USD ($) $ in Millions	Total	Series I Preferred Stock [Member]	Series H Preferred Stock [Member]	Preferred Stock [Member]	Preferred Stock [Member] Series I Preferred Stock [Member]	Preferred Stock [Member] Series H Preferred Stock [Member]	Common Stock [Member]	Common Stock Issuable [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Series I Preferred Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net [Member]	Treasury Stock [Member]
Beginning balance at Dec. 31, 2020	$ 16,187			$ 1,250			$ 80	$ 1	$ 6,617		$ 13,444	$ (62)	$ (5,143)
Total comprehensive income	1,794										1,859	(65)
Preferred stock cash dividends	(73)										(73)
Issuance of preferred stock		$ 495			$ 500					$ (5)
Stock-based compensation transactions, net	83								23		(1)		61
Common stock cash dividends	(583)										(583)
Ending balance at Dec. 31, 2021	17,903			1,750			80	1	6,635		14,646	(127)	(5,082)
Total comprehensive income	1,329										1,992	(663)
Common stock issued	8,286						10		3,256				5,020
Common stock awards converted	105								105
Preferred stock cash dividends	(97)										(97)
Issuance of preferred stock			$ 261			$ 261
Purchases of treasury stock	(1,800)												(1,800)
Stock-based compensation transactions, net	117								6		(1)		112
Common stock cash dividends	(786)										(786)
Ending balance at Dec. 31, 2022	25,318			2,011			90	1	10,002		15,754	(790)	(1,750)
Total comprehensive income	3,072										2,741	331
Preferred stock cash dividends	(100)										(100)
Purchases of treasury stock	(600)												(600)
Stock-based compensation transactions, net	136								18		(2)		120
Common stock cash dividends	(869)										(869)
Ending balance at Dec. 31, 2023	$ 26,957			$ 2,011			$ 90	$ 1	$ 10,020		$ 17,524	$ (459)	$ (2,230)