No definition available.

Name:	yi_BasisOfConsolidationAbstract
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Data Type:	xbrli:stringItemType
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- Definition

The extended term of agreement, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	yi_ExtendedTermOfAgreement
Namespace Prefix:	yi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum percentage of holding of equity interest in Foreign-Invested Telecommunications Enterprises if the enterprises are in E-commerce business.

+ References

No definition available.

+ Details

Name:	yi_MaximumPercentageOfHoldingOfEquityInterestsOfForeignInvestedTelecommunicationsEnterprisesIfThoseBusinessAreInECommerce
Namespace Prefix:	yi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of consecutive months to terminates the agreement or it is terminated in advance pursuant to other provisions of the agreement such as bankruptcy of one party or one party's failure to perform its obligation, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	yi_NumberOfConsecutiveMonthsToTerminateOrAdvanceTerminateOfAgreementFailureToPerformItsObligation
Namespace Prefix:	yi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Medicine Marketplaces

+ References

No definition available.

+ Details

Name:	yi_NumberOfMedicineMarketplaces
Namespace Prefix:	yi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of pharmacies.

+ References

No definition available.

+ Details

Name:	yi_NumberOfPharmacy
Namespace Prefix:	yi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of contribution to consolidated financing cash flow.

+ References

No definition available.

+ Details

Name:	yi_PercentageOfContributionToConsolidatedFinancingCashFlow
Namespace Prefix:	yi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of contribution to consolidated investing cash flow.

+ References

No definition available.

+ Details

Name:	yi_PercentageOfContributionToConsolidatedInvestingCashFlow
Namespace Prefix:	yi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of contribution to consolidated operating cash flow.

+ References

No definition available.

+ Details

Name:	yi_PercentageOfContributionToConsolidatedOperatingCashFlow
Namespace Prefix:	yi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of contribution to consolidated revenue.

+ References

No definition available.

+ Details

Name:	yi_PercentageOfContributionToConsolidatedRevenue
Namespace Prefix:	yi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of contribution to consolidated total assets.

+ References

No definition available.

+ Details

Name:	yi_PercentageOfContributionToConsolidatedTotalAssets
Namespace Prefix:	yi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of contribution to consolidated total liabilities.

+ References

No definition available.

+ Details

Name:	yi_PercentageOfContributionToConsolidatedTotalLiabilities
Namespace Prefix:	yi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of equity interest held in enterprises which have E-commerce business.

+ References

No definition available.

+ Details

Name:	yi_PercentageOfEquityHeldInEnterprisesWhichHaveECommerceBusiness
Namespace Prefix:	yi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The prior notice period for termination of proxy agreement, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	yi_PriorNoticePeriodForTerminationOfAgreement
Namespace Prefix:	yi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The term of agreement, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	yi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_ConsolidatedEntitiesAxis=yi_FormerVariableInterestEntityAndItsSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CounterpartyNameAxis=yi_YihaoPharmaceuticalChainMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=yi_ProxyAgreementOfVieMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=yi_ExclusiveSupportServiceAgreementOfVieMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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SUMMARY OF PRINCIPAL ACCOUNTING POLICIES - Basis of consolidation (Details) - item	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Basis of consolidation
Number of Medicine Marketplaces	1
Number of Pharmacy	1
Maximum percentage of holding of equity interest in enterprises which have E-commerce business	100.00%
Former VIE and former VIE's subsidiaries
Basis of consolidation
Percentage of contribution to consolidated total assets		32.00%
Percentage of contribution to consolidated total liabilities		36.00%
Percentage of contribution to consolidated revenue		41.00%	55.00%
Percentage of contribution to consolidated operating cash flow		22.00%	166.00%
Percentage of contribution to consolidated investing cash flow		30.00%	1.00%
Percentage of contribution to consolidated financing cash flow		18.00%	6.00%
Yihao Pharmaceutical Chain
Basis of consolidation
Percentage of holding of equity interest in enterprises which have E-commerce business	100.00%
Proxy Agreement
Basis of consolidation
Prior written notice period to terminate the agreement	30 days
Exclusive Support Service Agreement
Basis of consolidation
Term of agreement (in years)	10 years
Extended term of agreement (in years)	10 years
Consecutive months to terminate or advance terminate of agreement in failure to perform its obligation	6 months
China
Basis of consolidation
Number of Medicine Marketplaces	1
Number of Pharmacy	1