Interests in associates and joint ventures - Associates and Joint Ventures Commentary (Details) - USD ($)	6 Months Ended
Jun. 30, 2021	Dec. 31, 2020
Disclosure of associates [line items]
Interests in associates and joint ventures		$ 26,684,000,000
Bank of Communications Co., Limited
Disclosure of associates [line items]
Investment's fair value below carrying amount, period	9 years
Impairment loss	$ 0

Investment In Associates, Fair Value Below Carrying Amount, Period

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- Definition

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.

+ References

No definition available.

+ Details

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- Definition

The amount recognised as a reduction of the carrying amount of an asset or cash-generating unit to its recoverable amount. [Refer: Carrying amount [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2020-01-01
-Paragraph 130
-Subparagraph b
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-URIDate 2020-01-01

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 36
-IssueDate 2020-01-01
-Paragraph 130
-Subparagraph d
-Clause ii
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- Definition

The amount of investments in subsidiaries, joint ventures and associates in an entity's separate financial statements. [Refer: Associates [member]; Joint ventures [member]; Subsidiaries [member]; Investments in subsidiaries]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-IssueDate 2020-01-01
-Paragraph 10
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-URIDate 2020-01-01

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