Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Statement of Comprehensive Income [Abstract]
Net income	$ 1,364	$ 1,362	$ 3,838	$ 3,594
Net actuarial losses of defined benefit plans:
Adjustments, net of tax effect of ($1) and $5; $6 and $2	1	(11)	(19)	(5)
Recognized within net income, net of tax effect of ($1) and ($1); ($3) and ($3)	5	2	11	7
Prior service cost (credit) of defined benefit plans:
Recognized within net income, net of tax effect of $0 and $0; $0 and $0	0	1	0	1
Derivative instruments:
Change in fair value, net of tax effect of $0 and $0; $0 and $0	0	0	0	1
Available-for-sale investments:
Unrealized gains (losses), net of tax effect of $1 and ($4); $1 and ($2)	1	13	(1)	6
Other comprehensive income (loss), net of taxes	7	5	(9)	10
Total comprehensive income	$ 1,371	$ 1,367	$ 3,829	$ 3,604