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, 2022		$ 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
Other				0
Net income	$ 40,245				40,245
Preferred stock dividends					(1,115)
Common stock dividends ($1.25 and $1.05 per share and $3.55 and $3.05 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
Other				0
Net income	13,151				13,151
Preferred stock dividends					(386)
Common stock dividends ($1.25 and $1.05 per share and $3.55 and $3.05 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)
Beginning balance at Dec. 31, 2023	327,878	27,404	4,105	90,128	332,901	$ (161)	(10,443)	(116,217)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		2,496
Redemption		(8,250)
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				496
Other				14
Net income	44,466				44,466
Preferred stock dividends					(1,000)
Common stock dividends ($1.25 and $1.05 per share and $3.55 and $3.05 per share, respectively)					(10,240)
Other comprehensive income/(loss), after-tax	3,659						3,659
Repurchase								(14,652)
Reissuance								1,130
Ending balance at Sep. 30, 2024	345,836	21,650	4,105	90,638	365,966		(6,784)	(129,739)
Beginning balance at Jun. 30, 2024		23,900	4,105	90,328	356,924		(11,338)	(123,367)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance		0
Redemption		(2,250)
Shares issued and commitments to issue common stock for employee share-based compensation awards, and related tax effects				307
Other				3
Net income	12,898				12,898
Preferred stock dividends					(286)
Common stock dividends ($1.25 and $1.05 per share and $3.55 and $3.05 per share, respectively)					(3,570)
Other comprehensive income/(loss), after-tax	4,554						4,554
Repurchase								(6,423)
Reissuance								51
Ending balance at Sep. 30, 2024	$ 345,836	$ 21,650	$ 4,105	$ 90,638	$ 365,966		$ (6,784)	$ (129,739)