Structured entities - Conduits (Details) $ in Billions	12 Months Ended
Dec. 31, 2020 USD ($) conduit	Dec. 31, 2019 USD ($)
Disclosure of information about consolidated structured entities [line items]
Number of conduit types \| conduit	2
Securities investment conduits \| Solitaire
Disclosure of information about consolidated structured entities [line items]
Asset backed securities	$ 1.9	$ 2.1
Commercial paper held by HSBC	2.1	3.2
Multi-seller conduit
Disclosure of information about consolidated structured entities [line items]
Maximum exposure	$ 9.6	$ 12.4

Number Of Conduits

No definition available.

Name:	hsbc_NumberOfConduits
Namespace Prefix:	hsbc_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of debt instruments held that are backed by underlying assets. [Refer: Debt instruments held]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2020-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_AssetbackedDebtInstrumentsHeld
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of debt instruments held by the entity that were issued by a corporate entity. [Refer: Debt instruments held]

+ References

+ Details

Name:	ifrs-full_CorporateDebtInstrumentsHeld
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

Name:	ifrs-full_DisclosureOfInformationAboutConsolidatedStructuredEntitiesLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount that best represents the entity's maximum exposure to loss from its interests in structured entities. [Refer: Unconsolidated structured entities [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2020-01-01
-Paragraph 29
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2020-en-r&anchor=para_29_c&doctype=Standard
-URIDate 2020-01-01

+ Details

Name:	ifrs-full_MaximumExposureToLossFromInterestsInStructuredEntities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	ifrs-full_ConsolidatedStructuredEntitiesAxis=hsbc_SecuritiesInvestmentConduitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_SignificantInvestmentsInSubsidiariesAxis=hsbc_SolitaireMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ConsolidatedStructuredEntitiesAxis=hsbc_MultiSellerConduitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: