Consolidated Statement of Changes in Shareholders' Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning balance at Dec. 31, 2023	$ 23,799	$ 1,976	$ 504	$ 10,741	$ 27,957	$ (2,354)	$ (15,025)
Beginning balance (shares) at Dec. 31, 2023			503,880,000
Treasury stock, beginning balance (in shares) at Dec. 31, 2023							201,936,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	463				463
Other comprehensive income (loss)	(15)					(15)
Preferred stock issued	1,481	1,481
Preferred stock redeemed	(1,000)	(989)			(11)
Preferred stock dividends	208				208
Cash dividends declared:
Common stock dividends	(208)				(208)
Preferred stock dividends	(34)				(34)
Common stock acquired	(100)						$ (100)
Common stock acquired (shares)							1,365,000
Common stock awards exercised	49			(17)			$ 66
Common stock awards exercised (in shares)							(926,000)
Other	(2)				(1)		$ (1)
Ending balance at Mar. 31, 2024	24,433	2,468	$ 504	10,724	28,166	(2,369)	$ (15,060)
Ending balance (shares) at Mar. 31, 2024			503,880,000
Treasury stock, ending balance (in shares) at Mar. 31, 2024							202,375,000
Beginning balance at Dec. 31, 2024	$ 25,326	2,816	$ 504	10,722	29,582	(2,100)	$ (16,198)
Beginning balance (shares) at Dec. 31, 2024	503,879,642		503,880,000
Treasury stock, beginning balance (in shares) at Dec. 31, 2024	215,113,190						215,113,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 644				644
Other comprehensive income (loss)	308					308
Preferred stock issued	743	743
Preferred stock dividends	220				220
Cash dividends declared:
Common stock dividends	(220)				(220)
Preferred stock dividends	(46)				(46)
Common stock acquired	(100)						$ (100)
Common stock acquired (shares)							1,004,000
Common stock awards exercised	37			(29)			$ 66
Common stock awards exercised (in shares)							(905,000)
Other	0				(1)		$ 1
Other (shares)							(9,000)
Ending balance at Mar. 31, 2025	$ 26,692	$ 3,559	$ 504	$ 10,693	$ 29,959	$ (1,792)	$ (16,231)
Ending balance (shares) at Mar. 31, 2025	503,879,642		503,880,000
Treasury stock, ending balance (in shares) at Mar. 31, 2025	215,203,413						215,203,000