Pension and other postretirement benefits - Schedule of Fair Value of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 430	$ 434	$ 449
Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,734	2,463	2,524
Level 1 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	20	19
Level 1 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,790	1,966
Level 2 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	408	413
Level 2 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	823	376
Level 3 | United States
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2	4
Level 3 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2
Level 3 | Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	121	121	139
Level 3 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	121	121
Cash and cash equivalents | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	3
Cash and cash equivalents | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	60	54
Cash and cash equivalents | Level 1 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	3
Cash and cash equivalents | Level 1 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	56	32
Cash and cash equivalents | Level 2 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents | Level 2 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	22
Cash and cash equivalents | Level 3 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and cash equivalents | Level 3 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity instruments | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	90	87
Equity instruments | United States | Pension Plans | Developed markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	82	78
Equity instruments | United States | Pension Plans | Emerging markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	9
Equity instruments | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	589	558
Equity instruments | Non-U.S. | Pension Plans | Developed markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	559	521
Equity instruments | Non-U.S. | Pension Plans | Emerging markets
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	30	37
Equity instruments | Level 1 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity instruments | Level 1 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	484	499
Equity instruments | Level 2 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	90	87
Equity instruments | Level 2 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	105	59
Equity instruments | Level 3 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity instruments | Level 3 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Debt instrument | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	318	326
Debt instrument | United States | Pension Plans | Non-government debt instruments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	210	226
Debt instrument | United States | Pension Plans | Government fixed interest instruments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	108	100
Debt instrument | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,581	1,437
Debt instrument | Non-U.S. | Pension Plans | Non-government debt instruments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	275	245
Debt instrument | Non-U.S. | Pension Plans | Government fixed interest instruments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	451	721
Debt instrument | Non-U.S. | Pension Plans | Government inflation-protected bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	810	434
Debt instrument | Non-U.S. | Pension Plans | Asset-backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	45	37
Debt instrument | Level 1 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Debt instrument | Level 1 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,093	1,226
Debt instrument | Level 2 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	318	326
Debt instrument | Level 2 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	488	211
Debt instrument | Level 3 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Debt instrument | Level 3 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Real estate | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Real estate | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	234	200
Real estate | Level 1 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Real estate | Level 1 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	86	111
Real estate | Level 2 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Real estate | Level 2 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	138	81
Real estate | Level 3 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Real estate | Level 3 | Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	8	14
Real estate | Level 3 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	8
Derivatives | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Derivatives | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	51	(15)
Derivatives | Level 1 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Derivatives | Level 1 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	8
Derivatives | Level 2 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Derivatives | Level 2 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	41	(23)
Derivatives | Level 3 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Derivatives | Level 3 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment funds | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16	16
Investment funds | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	95	108
Investment funds | Level 1 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16	16
Investment funds | Level 1 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	58	87
Investment funds | Level 2 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment funds | Level 2 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	37	21
Investment funds | Level 3 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Investment funds | Level 3 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Assets held by insurance company | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Assets held by insurance company | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	104	107
Assets held by insurance company | Level 1 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Assets held by insurance company | Level 1 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Assets held by insurance company | Level 2 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Assets held by insurance company | Level 2 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	2
Assets held by insurance company | Level 3 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Assets held by insurance company | Level 3 | Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	101	105	117
Assets held by insurance company | Level 3 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	101	105
Other | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2
Other | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	20	14
Other | Level 1 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other | Level 1 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	3
Other | Level 2 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other | Level 2 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7	3
Other | Level 3 | United States
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2	4
Other | Level 3 | United States | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2	2
Other | Level 3 | Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10	8	$ 8
Other | Level 3 | Non-U.S. | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 10	$ 8