Fair Value Measurements and Financial Instruments - Debt Excluding Capital Leases (Detail) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument fair value	$ 150,756	$ 148,906
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument fair value	142,510	139,041
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument fair value	86,843	84,385
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument fair value	55,667	54,656
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt instrument fair value	$ 0	$ 0