Name:	sny_EmployeeBenefitPlanParticipantContributionAfterTaxMaximumContributionPercentage
Namespace Prefix:	sny_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Period within which the eligible participant employees can opt out from the automatic enrolled scheme under employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

No definition available.

Name:	sny_EmployeeBenefitPlanParticipantContributionAutomaticDeferralOptOutPeriod
Namespace Prefix:	sny_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Percentage of annual increase of the eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

No definition available.

Name:	sny_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRateAnnualIncrease
Namespace Prefix:	sny_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

The maximum percentage by which a participant's contribution is automatically increased each year under the plan's escalation feature.

No definition available.

Name:	sny_EmployeeBenefitPlanParticipantContributionMaximumAutomaticDeferralAnnualIncreasePercentage
Namespace Prefix:	sny_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Name:	us-gaap-ebp_EmployeeBenefitPlanDescriptionOfPlanLineItems
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Percentage of employer matching contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Name:	us-gaap-ebp_EmployeeBenefitPlanEmployerContributionMatchingPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of participant compensation eligible for employer matching contribution for participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

Name:	us-gaap-ebp_EmployeeBenefitPlanEmployerContributionParticipantCompensationMatchedPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

Name:	us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of maximum pretax annual compensation that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), is permitted to contribute to total pretax annual compensation.