Intangible assets - Main amortization rates (Details)	12 Months Ended
Dec. 31, 2021
Exploration rights
Intangible assets
Description of useful life, intangible assets other than goodwill	UOP
Transport rights of natural gas
Intangible assets
Amortisation rate, intangible assets other than goodwill	3.00%
Other concessions, licenses, trademarks and similar items \| Minimum
Intangible assets
Amortisation rate, intangible assets other than goodwill	3.00%
Other concessions, licenses, trademarks and similar items \| Maximum
Intangible assets
Amortisation rate, intangible assets other than goodwill	33.00%
Industrial patents and intellectual property right \| Minimum
Intangible assets
Amortisation rate, intangible assets other than goodwill	20.00%
Industrial patents and intellectual property right \| Maximum
Intangible assets
Amortisation rate, intangible assets other than goodwill	33.00%
Capitalized costs for customer acquisition \| Minimum
Intangible assets
Amortisation rate, intangible assets other than goodwill	17.00%
Capitalized costs for customer acquisition \| Maximum
Intangible assets
Amortisation rate, intangible assets other than goodwill	33.00%
Other intangible assets \| Minimum
Intangible assets
Amortisation rate, intangible assets other than goodwill	4.00%
Other intangible assets \| Maximum
Intangible assets
Amortisation rate, intangible assets other than goodwill	20.00%

The amortisation rate used for intangible assets other than goodwill. [Refer: Intangible assets other than goodwill]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 38
-IssueDate 2021-01-01
-Paragraph 118
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=38&code=ifrs-tx-2021-en-r&anchor=para_118_a&doctype=Standard
-URIDate 2021-03-24

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Description of useful life used for intangible assets other than goodwill. [Refer: Intangible assets other than goodwill]

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