Other financial assets - Securities per issuing entity (Details) € in Millions	12 Months Ended
Dec. 31, 2023 EUR (€)
Amortized cost
Other financial assets
Amortized cost	€ 61
Nominal value	61
Fair value	59
Quoted bonds issued by sovereign states \| Amortized cost
Other financial assets
Amortized cost	56
Nominal value	56
Fair value	54
Maximum value of sovereign states bonds included in other category	10
Quoted bonds issued by sovereign states, Fixed rate bonds \| Amortized cost \| Italy
Other financial assets
Amortized cost	19
Nominal value	19
Fair value	€ 17
Maturity date	from 2024 to 2031
Rating - Moody's	Baa3
Rating - S&P	BBB
Quoted bonds issued by sovereign states, Fixed rate bonds \| Amortized cost \| Italy \| Minimum
Other financial assets
Nominal rate of return (%)	0.00%
Quoted bonds issued by sovereign states, Fixed rate bonds \| Amortized cost \| Italy \| Maximum
Other financial assets
Nominal rate of return (%)	2.65%
Quoted bonds issued by sovereign states, Fixed rate bonds \| Amortized cost \| Foreign (outside Italy)
Other financial assets
Amortized cost	€ 25
Nominal value	25
Fair value	€ 25
Maturity date	from 2024 to 2027
Rating - Moody's	from Aa1 to Baa2
Rating - S&P	from AA+ to BBB-
Quoted bonds issued by sovereign states, Fixed rate bonds \| Amortized cost \| Foreign (outside Italy) \| Minimum
Other financial assets
Nominal rate of return (%)	0.10%
Quoted bonds issued by sovereign states, Fixed rate bonds \| Amortized cost \| Foreign (outside Italy) \| Maximum
Other financial assets
Nominal rate of return (%)	5.00%
Quoted bonds issued by sovereign states, Floating rate bonds \| Amortized cost \| Italy
Other financial assets
Amortized cost	€ 12
Nominal value	12
Fair value	€ 12
Maturity date	from 2024 to 2026
Rating - Moody's	Baa3
Rating - S&P	BBB
Quoted bonds issued by sovereign states, Floating rate bonds \| Amortized cost \| Italy \| Minimum
Other financial assets
Nominal rate of return (%)	4.62%
Quoted bonds issued by sovereign states, Floating rate bonds \| Amortized cost \| Italy \| Maximum
Other financial assets
Nominal rate of return (%)	5.07%
European Bank of Investments [member]
Other financial assets
Amortized cost	€ 5
Nominal value	5
Fair value	€ 5
Nominal rate of return (%)	3.98%
Maturity date	from 2023 to 2024
European Bank of Investments [member] \| Foreign (outside Italy)
Other financial assets
Rating - Moody's	Aaa
Rating - S&P	AAA

Disclosure Of Financial Assets Explanatory.

No definition available.

Name:	e_DisclosureOfFinancialAssetsExplanatoryLineItems
Namespace Prefix:	e_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The credit grades that have been provided by Moody's.

+ References

No definition available.

+ Details

Name:	e_ExternalRatingByMoodysGrade
Namespace Prefix:	e_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The description of external rating by s&p grade.

+ References

No definition available.

+ Details

Name:	e_ExternalRatingBySpGrade
Namespace Prefix:	e_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The maturity date of the securities.

+ References

No definition available.

+ Details

Name:	e_FinancialAssetsMaturityDate
Namespace Prefix:	e_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

It represent the financial assets, nominal rate of return of securities.

+ References

No definition available.

+ Details

Name:	e_FinancialAssetsNominalRateOfReturn
Namespace Prefix:	e_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of maximum value of sovereign states bonds included in other category.

+ References

No definition available.

+ Details

Name:	e_MaximumValueOfSovereignStatesBondsIncludedInOtherCategory
Namespace Prefix:	e_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of financial assets at amortised cost. The amortised cost is the amount at which financial assets are measured at initial recognition minus principal repayments, plus or minus the cumulative amortisation using the effective interest method of any difference between that initial amount and the maturity amount, and adjusted for any impairment. [Refer: Financial assets]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2023-01-01
-Paragraph 8
-Subparagraph f
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2023-en-r&anchor=para_8_f&doctype=Standard
-URIDate 2023-03-23

+ Details

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

- Definition

The fair value of financial assets. [Refer: At fair value [member]; Financial assets]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2023-01-01
-Paragraph 25
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2023-en-r&anchor=para_25&doctype=Standard
-URIDate 2023-03-23

+ Details

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

- Definition

The nominal or face amount of a financial instrument, used to calculate payments made on that instrument.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2023-03-23

+ Details

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

- Details

Name:	ifrs-full_CategoriesOfFinancialAssetsAxis=ifrs-full_FinancialAssetsAtAmortisedCostCategoryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=e_QuotedBondsIssuedBySovereignStateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=e_QuotedBondsIssuedBySovereignStatesFixedRateBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_GeographicalAreasAxis=country_IT
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_GeographicalAreasAxis=ifrs-full_ForeignCountriesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=e_QuotedBondsIssuedBySovereignStatesFloatingRateBondsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialAssetsAxis=e_EuropeanBankOfInvestmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: