Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Preferred stock	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income/(loss)	Treasury stock, at cost
Beginning balance at Dec. 31, 2020		$ 30,063	$ 4,105	$ 88,394	$ 236,990	$ 7,986	$ (88,184)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		1,500
Redemption		0
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				(363)
Other				(26)
Net income	$ 14,300				14,300
Dividends declared:
Preferred stock					(379)
Common stock ($1.00 and $0.90 per share)					(2,760)
Other comprehensive income/(loss), after-tax	(6,945)					(6,945)
Repurchase							(4,999)
Reissuance							1,032
Ending balance at Mar. 31, 2021	280,714	31,563	4,105	88,005	248,151	1,041	(92,151)
Beginning balance at Dec. 31, 2021	294,127	34,838	4,105	88,415	272,268	(84)	(105,415)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		0
Redemption		(2,000)
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				(155)
Other				0
Net income	8,282				8,282
Dividends declared:
Preferred stock					(397)
Common stock ($1.00 and $0.90 per share)					(2,976)
Other comprehensive income/(loss), after-tax	(9,483)					(9,483)
Repurchase							(2,500)
Reissuance							1,001
Ending balance at Mar. 31, 2022	$ 285,899	$ 32,838	$ 4,105	$ 88,260	$ 277,177	$ (9,567)	$ (106,914)