Consolidated net cash/(debt) - Analysis of changes in consolidated net cash/(debt) (Parenthetical) (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of financial liabilities [Abstract]
Borrowings	$ 14,115	$ 12,752
Borrowings and other financial liabilities	14,713	13,920
Total other current financial liabilities	1,372	1,073
Other non-current financial liabilities	13,341	12,847
Overdrafts	0	1
Other differences to cash and cash equivalents in statement of cash flows	117
Cash and cash equivalents included in Assets held for sale	0	117
Highly liquid financial assets held in managed investment funds classified as held for trading	2,584	2,522
Borrowings (including finance leases) Excluding Overdraft [member]
Disclosure of financial liabilities [Abstract]
Total other current financial liabilities		761
Other current non-financial liabilities		407
Over Draft
Disclosure of financial liabilities [Abstract]
Overdrafts	0	1
Borrowings Excluding Overdrafts, Including Lease Liabilities [Member]
Disclosure of financial liabilities [Abstract]
Borrowings	14,115	12,751
Net Other Financial Liabilities [Member]
Disclosure of financial liabilities [Abstract]
Total other current financial liabilities	350	761
Other non-current financial liabilities	$ 248	$ 407

The amount that has been withdrawn from an account in excess of existing cash balances. This is considered a short-term extension of credit by the bank. [Refer: Cash and cash equivalents]

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The amount of cash and cash equivalents that are classified as a part of a disposal group held for sale. [Refer: Cash and cash equivalents; Disposal groups classified as held for sale [member]]

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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The amount of financial assets at fair value through profit or loss classified as held for trading. A financial asset is classified as held for trading if: (a) it is acquired principally for the purpose of selling it in the near term; (b) on initial recognition it is part of a portfolio of identified financial instruments that are managed together and for which there is evidence of a recent actual pattern of short-term profit-taking; or (c) it is a derivative (except for a derivative that is a financial guarantee contract or a designated and effective hedging instrument). [Refer: At fair value [member]; Financial assets at fair value through profit or loss]

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The amount of current financial liabilities that the entity does not separately disclose in the same statement or note. [Refer: Other financial liabilities; Current financial liabilities]

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The amount of differences between cash and cash equivalents in the statement of cash flows and the statement of financial position that the entity does not separately disclose in the same statement or note. [Refer: Cash and cash equivalents]

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The amount of non-current financial liabilities that the entity does not separately disclose in the same statement or note. [Refer: Other financial liabilities]

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Borrowings and other financial liabilities.

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