Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 2,201	$ 1,753
Net actuarial losses of defined benefit plans:
Adjustments, net of tax effect of ($2) and ($2)	6	5
Recognized within net income, net of tax effect of ($1) and ($3)	2	8
Available-for-sale investments:
Unrealized losses, net of tax effect of $1 and $0	(4)	0
Other comprehensive income (loss), net of taxes	4	13
Total comprehensive income	$ 2,205	$ 1,766