Pension and postretirement benefits - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 28, 2024	Sep. 30, 2023	Sep. 28, 2024	Sep. 30, 2023
Pension
Defined Benefit Plan Disclosure [Line Items]
Curtailment (gain) loss, net	$ 3		$ 3
Service cost	2	$ 1	6	$ 1
Nonpension postretirement
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 1	$ 3	$ 1

Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 715
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 715
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration