Basis of Presentation and Significant Accounting Policies and Practices - Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Basic EPS:
Net income	$ 6,510	$ 8,749	$ 7,769
Income allocated to RSUs	(34)	(40)	(33)
Income allocated to common stock for basic EPS	$ 6,476	$ 8,709	$ 7,736
Weighted average number of shares outstanding, basic (in shares)	908	916	923
Basic earnings per common share (in dollars per share)	$ 7.13	$ 9.51	$ 8.38
Dilutive effect of stock compensation plans	8	10	13
Diluted EPS:
Net income	$ 6,510	$ 8,749	$ 7,769
Income allocated to RSUs	(33)	(39)	(33)
Income allocated to common stock for diluted EPS	$ 6,477	$ 8,710	$ 7,736
Weighted average number of shares outstanding, diluted (in shares)	916	926	936
Diluted earnings per common share (in dollars per share)	$ 7.07	$ 9.41	$ 8.26