Income taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Examination
Undistributed earnings of foreign subsidiaries	$ 15,000
Income taxes paid	2,949	$ 3,076	$ 1,759
Valuation allowance for deferred tax assets	934	1,014
Penalties	36	49	$ 54
Interest and penalties, accrued	$ 135	95
Final tax assessed, period	10 years
Internal Revenue Service (IRS)
Income Tax Examination
Final tax assessed		490
Interest		250
Tax benefit		$ (41)
U.S. state taxing jurisdictions
Income Tax Examination
Deferred tax assets for losses and credit carryforwards	$ 42
Valuation allowance for deferred tax assets	95
Domestic Tax Authority
Income Tax Examination
Capital loss and credit carryforwards	157
Valuation allowance for deferred tax assets	157
Non-U.S. taxing jurisdictions
Income Tax Examination
Deferred tax assets for losses and credit carryforwards	838
Valuation allowance for deferred tax assets	682
Primarily over the next 20 years | U.S. state taxing jurisdictions
Income Tax Examination
Deferred tax assets for losses and credit carryforwards	86
Net Operating Loss Carryforward due to Expire in Next Twelve Months and Beyond But Not Unlimited | Non-U.S. taxing jurisdictions
Income Tax Examination
Deferred tax assets for losses and credit carryforwards	$ 266