Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Preferred stock	Common stock	Additional paid-in capital	Retained earnings	Retained earnings Cumulative effect of change in accounting principles	Accumulated other comprehensive income/(loss)	Treasury stock, at cost
Beginning balance at Dec. 31, 2021		$ 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				450
Net income	$ 26,668				26,668
Dividends declared:
Preferred stock					(1,239)
Common stock ($1.05 and $1.00 per share and $3.05 and $3.00 per share, respectively)					(8,921)
Other comprehensive income/(loss), after-tax	(19,050)						(19,050)
Repurchase								(3,122)
Reissuance								1,105
Ending balance at Sep. 30, 2022	288,018	32,838	4,105	88,865	288,776		(19,134)	(107,432)
Beginning balance at Jun. 30, 2022		32,838	4,105	88,614	282,445		(14,369)	(107,490)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		0
Redemption		0
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				251
Net income	9,737				9,737
Dividends declared:
Preferred stock					(432)
Common stock ($1.05 and $1.00 per share and $3.05 and $3.00 per share, respectively)					(2,974)
Other comprehensive income/(loss), after-tax	(4,765)						(4,765)
Repurchase								0
Reissuance								58
Ending balance at Sep. 30, 2022	288,018	32,838	4,105	88,865	288,776		(19,134)	(107,432)
Beginning balance at Dec. 31, 2022	292,332	27,404	4,105	89,044	296,456	$ 449	(17,341)	(107,336)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		0
Redemption		0
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				855
Net income	40,245				40,245
Dividends declared:
Preferred stock					(1,115)
Common stock ($1.05 and $1.00 per share and $3.05 and $3.00 per share, respectively)					(8,991)
Other comprehensive income/(loss), after-tax	237						237
Repurchase								(7,658)
Reissuance								1,017
Ending balance at Sep. 30, 2023	317,371	27,404	4,105	89,899	327,044		(17,104)	(113,977)
Beginning balance at Jun. 30, 2023		27,404	4,105	89,578	317,359		(14,290)	(111,640)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		0
Redemption		0
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				321
Net income	13,151				13,151
Dividends declared:
Preferred stock					(386)
Common stock ($1.05 and $1.00 per share and $3.05 and $3.00 per share, respectively)					(3,080)
Other comprehensive income/(loss), after-tax	(2,814)						(2,814)
Repurchase								(2,387)
Reissuance								50
Ending balance at Sep. 30, 2023	$ 317,371	$ 27,404	$ 4,105	$ 89,899	$ 327,044		$ (17,104)	$ (113,977)