Supplemental financial information - Amounts Reclassified out of AOCI (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net (OI&E)		$ 7	$ 73	$ 22	$ 119
Provision for income taxes		(390)	(311)	(715)	(497)
Net income		2,291	1,931	4,492	3,684
Reclassification out of Accumulated Other Comprehensive Income | Net actuarial losses of defined benefit plans
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net (OI&E)	[1]	20	10	23	21
Provision for income taxes		(4)	(2)	(5)	(5)
Net income		$ 16	$ 8	$ 18	$ 16

[1] Detailed in Note 5