Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 7,769	$ 5,595	$ 5,017
Net actuarial losses of defined benefit plans:
Adjustments, net of tax effect of ($56), $3 and ($37)	175	(41)	88
Recognized within net income, net of tax effect of ($8), ($9) and ($13)	29	29	38
Prior service credit of defined benefit plans:
Recognized within net income, net of tax effect of $0, $0 and $0	(1)	(1)	0
Other comprehensive income (loss), net of taxes	203	(13)	126
Total comprehensive income	$ 7,972	$ 5,582	$ 5,143