Debt and Derivatives - Borrowings and Repayments (Detail) - USD ($) $ in Millions	1 Months Ended				12 Months Ended
	Oct. 31, 2023	Aug. 31, 2023	Jul. 31, 2023	Feb. 28, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt
New borrowings					$ 21,306	$ 8,688	$ 7,948
Debt repayments					20,394	$ 7,328	8,404
Premiums paid on early extinguishment of debt							$ 211
Scheduled Debt Payments
2024					1,192
2025					1,355
2026					713
2027					1,198
2028					892
Thereafter					11,002
Commercial Paper Program [Member]
Debt
Commercial paper repayments					18,700
Commercial paper borrowings					17,800
Term Loan [Member]
Debt
Debt repayments		$ 1,000
4.625% senior notes due 2030 and 2033 [Member]
Debt
Interest rate (as a percent)				4.625%
New borrowings				$ 1,240
4.625% senior notes due 2030 [Member]
Debt
Debt instrument face amount				750
4.625% senior notes due 2033 [Member]
Debt
Debt instrument face amount				$ 500
Senior Notes 4.875 Percent Due 2029 And 2034 [Member]
Debt
Interest rate (as a percent)			4.875%
New borrowings			$ 1,970
Senior Notes 4.875 Percent Due 2029 [Member]
Debt
Debt instrument face amount			750
Senior Notes 4.875 Percent Due 2034 [Member]
Debt
Debt instrument face amount			$ 1,250
Tax Exempt Bonds [Member]
Debt
New borrowings					300
Debt repayments					65
Financing leases and other [Member]
Debt
Debt repayments					120
Non-cash financing lease incurred					93
Financing leases and other [Member] | Low income housing investments [Member]
Debt
Note issued	$ 183				$ 183
Senior Notes 2.4 Percent Due May 2023 [Member]
Debt
Interest rate (as a percent)				2.40%
Debt repayments				$ 500