Employee compensation and benefits - Income statement charge (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee Compensation And Benefits [Abstract]
Defined benefit pension plans	$ 243	$ 146	$ 176
Defined contribution pension plans	767	775	758
Pension plans	1,010	921	934
Defined benefit and contribution healthcare plans	27	25	15
Post-employment benefits	$ 1,037	$ 946	$ 949

Employee Compensation And Benefits [Abstract]

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- Definition

Post-Employment Benefit Expense, Defined Benefit And Contribution Healthcare Plans

+ References

No definition available.

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- Definition

Post-Employment Benefit Expense, Defined Benefit Plans, Defined Contribution Plans, And Defined Benefit And Contribution Healthcare Plans

+ References

No definition available.

+ Details

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- Definition

Post-employment Benefit Expense, Defined Benefit Plans And Defined Contribution Plans

+ References

No definition available.

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- Definition

The amount of post-employment benefit expense included in profit or loss relating to defined benefit plans. [Refer: Profit (loss); Defined benefit plans [member]] [Contrast: Increase (decrease) in net defined benefit liability (asset) resulting from expense (income) in profit or loss]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

The amount of post-employment benefit expense relating to defined contribution plans. Defined contribution plans are post-employment benefit plans under which an entity pays fixed contributions into a separate entity (a fund) and will have no legal or constructive obligation to pay further contributions if the fund does not hold sufficient assets to pay all employee benefits relating to employee service in the current and prior periods.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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