Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 1,708	$ 2,201
Net actuarial losses of defined benefit plans:
Adjustments, net of tax effect of $1 and ($2)	(2)	6
Recognized within net income, net of tax effect of ($1) and ($1)	3	2
Derivative instruments:
Change in fair value, net of tax effect of $1 and $0	(2)	0
Available-for-sale investments:
Unrealized gains (losses), net of tax effect of $0 and $1	3	(4)
Other comprehensive income (loss), net of taxes	2	4
Total comprehensive income	$ 1,710	$ 2,205