Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 1,722	$ 2,291	$ 3,430	$ 4,492
Net actuarial losses of defined benefit plans:
Adjustments, net of tax effect of ($2) and $8; ($1) and $6	2	(40)	0	(34)
Recognized within net income, net of tax effect of ($1) and ($4); ($2) and ($5)	3	16	6	18
Derivative instruments:
Change in fair value, net of tax effect of ($1) and $0; $0 and $0	3	0	1	0
Available-for-sale investments:
Unrealized gains (losses), net of tax effect of $0 and $1; $0 and $2	(2)	(3)	1	(7)
Other comprehensive income (loss), net of taxes	6	(27)	8	(23)
Total comprehensive income	$ 1,728	$ 2,264	$ 3,438	$ 4,469