Postemployment benefit plans - Schedule of benefit obligation in excess of plan assets (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
U.S. Pension Benefits
Pension plans with projected benefit obligation in excess of plan assets:
Projected benefit obligation	$ 623	$ 627
Fair value of plan assets	0	0
Pension plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	623	627
Fair value of plan assets	0	0
Non-U.S. Pension Benefits
Pension plans with projected benefit obligation in excess of plan assets:
Projected benefit obligation	412	370
Fair value of plan assets	54	43
Pension plans with accumulated benefit obligation in excess of plan assets:
Accumulated benefit obligation	300	279
Fair value of plan assets	$ 19	$ 7

Amount of plan asset for defined benefit pension plan with projected benefit obligation in excess of plan assets.

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- Definition

Amount of projected benefit obligation for defined benefit pension plan with projected benefit obligation in excess of plan assets.

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- Definition

Amount of accumulated benefit obligation for defined benefit plan with accumulated benefit obligation in excess of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480482/715-20-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 715
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-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Amount of plan asset for defined benefit plan with accumulated benefit obligation in excess of plan assets.

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