Report Of The Directors Financial Review Risk Report - Credit risk, Description and exposure (Details)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Credit risk
Disclosure of credit risk exposure [line items]
Percentage of insurance contracts assessed as satisfactory or higher that is neither past due nor impaired	100.00%	100.00%

Exposure To Credit Risk On Reinsurers' Share Of Liabilities Under Insurance Contracts, Neither Past Due Nor Impaired, Percentage

No definition available.

Name:	hsbc_ExposureToCreditRiskOnReinsurersShareOfLiabilitiesUnderInsuranceContractsNeitherPastDueNorImpairedPercentage
Namespace Prefix:	hsbc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration