Post-retirement benefits - Summary of funding policy and contributions to plans (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disclosure of net defined benefit liability (asset) [Line Items]
Contributions to defined benefit plans	$ 211	$ 464	$ 201
Contributions to defined contribution plans	363	311	261
Total	574	$ 775	$ 462
Pension benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Contributions to defined benefit plans	171
Contributions to defined contribution plans	361
Total	532
Other benefits
Disclosure of net defined benefit liability (asset) [Line Items]
Contributions to defined benefit plans	40
Contributions to defined contribution plans	2
Total	$ 42

The decrease (increase) in net defined benefit liability (asset) resulting from contributions to a defined benefit plan by the employer. [Refer: Net defined benefit liability (asset); Defined benefit plans [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2021-01-01
-Paragraph 141
-Subparagraph f
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_141_f&doctype=Standard
-URIDate 2021-03-24

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- Definition

The decrease (increase) in the net defined benefit liability (asset) resulting from contributions to a defined benefit plan. [Refer: Net defined benefit liability (asset); Defined benefit plans [member]]

+ References

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- Definition

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- Definition

Contributions to Defined Contribution Plans

+ References

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