Consolidated Statement of Changes in Stockholders' Equity - USD ($) $ in Millions	Total	Preferred Stock, end of period	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss) ("AOCI"), net of tax	Treasury Stock, Common	Treasury Stock, Common Stock Compensation Plan
Beginning balance at Dec. 31, 2020			$ 4	$ 4,322	$ 13,918	$ 1,170	$ (1,192)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under incentive and stock compensation plans and other				(90)
Stock-based compensation plans expense				116
Treasury Stock, Retired, Cost Method, Amount			0	(1,039)			(1,039)
Net income	$ 2,371				2,371
Dividends declared on preferred stock					(21)
Dividends declared on common stock					(498)
Treasury stock acquired	(1,700)						(1,702)
Stock Issued During Period, Value, Treasury Stock Reissued								$ 146
Net shares acquired related to employee incentive and stock compensation plans							(31)
Other Comprehensive Income (Loss), Net of Tax						(977)
Ending balance at Dec. 31, 2021	$ 17,805	$ 334	$ 4	3,309	15,770	128	(1,740)
Preferred Stock, Shares Outstanding, Ending Balance at Dec. 31, 2021		13,800
Common Shares Outstanding, beginning of period at Dec. 31, 2020			358,489,000
Common Shares Outstanding (in thousands)
Treasury stock acquired	(25,900,000)		(25,878,000)
Issuance of shares under incentive and stock compensation plans and other			2,902,000
Return of shares under incentive and stock compensation plans to treasury stock			(587,000)
Common Shares Outstanding, end of period at Dec. 31, 2021			334,926,000
Common Shares Outstanding (in thousands)
Cash dividends declared per common share	$ 1.44
Preferred Stock, Dividends Per Share, Declared	$ 1,500
Issuance of shares under incentive and stock compensation plans and other				(154)
Stock-based compensation plans expense				131
Treasury Stock, Retired, Cost Method, Amount			$ (1)	(1,391)			(1,392)
Net income	$ 1,819				1,819
Dividends declared on preferred stock					(21)
Dividends declared on common stock					(510)
Treasury stock acquired	(1,600)						(1,550)
Stock Issued During Period, Value, Treasury Stock Reissued								183
Net shares acquired related to employee incentive and stock compensation plans							(58)
Other Comprehensive Income (Loss), Net of Tax						(3,969)
Ending balance at Dec. 31, 2022	$ 13,676	$ 334	$ 3	1,895	17,058	(3,841)	(1,773)
Preferred Stock, Shares Outstanding, Ending Balance at Dec. 31, 2022		13,800
Common Shares Outstanding (in thousands)
Treasury stock acquired	(22,300,000)		(22,273,000)
Issuance of shares under incentive and stock compensation plans and other			3,285,000
Return of shares under incentive and stock compensation plans to treasury stock			(827,000)
Common Shares Outstanding, end of period at Dec. 31, 2022			315,111,000
Common Shares Outstanding (in thousands)
Cash dividends declared per common share	$ 1.58
Preferred Stock, Dividends Per Share, Declared	$ 1,500
Issuance of shares under incentive and stock compensation plans and other				(153)
Stock-based compensation plans expense				125
Treasury Stock, Retired, Cost Method, Amount			$ 0	(1,219)			(1,219)
Net income	$ 2,504				2,504
Dividends declared on preferred stock					(21)
Dividends declared on common stock					(534)
Treasury stock acquired	(1,400)						(1,414)
Stock Issued During Period, Value, Treasury Stock Reissued								$ 207
Net shares acquired related to employee incentive and stock compensation plans							(55)
Other Comprehensive Income (Loss), Net of Tax						992
Ending balance at Dec. 31, 2023	$ 15,327	$ 334	$ 3	$ 648	$ 19,007	$ (2,849)	$ (1,816)
Preferred Stock, Shares Outstanding, Ending Balance at Dec. 31, 2023		13,800
Common Shares Outstanding (in thousands)
Treasury stock acquired	(19,200,000)		(19,238,000)
Issuance of shares under incentive and stock compensation plans and other			3,299,000
Return of shares under incentive and stock compensation plans to treasury stock			(700,000)
Common Shares Outstanding, end of period at Dec. 31, 2023			298,472,000
Common Shares Outstanding (in thousands)
Cash dividends declared per common share	$ 1.75
Preferred Stock, Dividends Per Share, Declared	$ 1,500