Earnings Per Common Share - Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Earnings per common share
Net income	$ 8,161	$ 7,067
Preferred stock dividends	(505)	(467)
Net income applicable to common shareholders	$ 7,656	$ 6,600
Average common shares issued and outstanding (in shares)	8,065.9	8,136.8
Earnings per common share (in dollars per share)	$ 0.95	$ 0.81
Diluted earnings per common share
Net income applicable to common shareholders	$ 7,656	$ 6,600
Add preferred stock dividends due to assumed conversions	56	0
Net income allocated to common shareholders	$ 7,712	$ 6,600
Average common shares issued and outstanding (in shares)	8,065.9	8,136.8
Dilutive potential common shares (in shares)	116.4	65.3
Total diluted average common shares issued and outstanding (in shares)	8,182.3	8,202.1
Diluted earnings per common share (in dollars per share)	$ 0.94	$ 0.80