Fixed assets (Narrative) (Details) - EUR (€) € in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Disclosure of detailed information about property, plant and equipment [line items]
Fixed Assets	€ 264,095	€ 114,389
Useful lives	20-40 years
Capitalized borrowing costs	€ 2,369
Italy [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Fixed Assets
Useful lives	20 years
Spain [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Fixed Assets	€ 217,339	€ 97,327
Depreciation expenses	€ 4,383
Useful lives	25 years
Netherlands [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Depreciation expenses	€ 1,457
Useful lives	12 years
Photovoltaic Plants [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Fixed Assets	€ 233,626
Biogas Installations [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Fixed Assets	37,379
Manara PSP [Member] \| Euro [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Fixed Assets	€ 16,607

The amount of interest and other costs that an entity incurs in connection with the borrowing of funds that are directly attributable to the acquisition, construction or production of a qualifying asset and which form part of the cost of that asset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition

The amount of depreciation of property, plant and equipment. [Refer: Depreciation and amortisation expense; Property, plant and equipment]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2020-01-01
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- Definition

Description of useful life used for property, plant and equipment. [Refer: Property, plant and equipment]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2020-01-01
-Paragraph 73
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- Definition

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

+ References

No definition available.

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- Definition

The amount of tangible assets that: (a) are held for use in the production or supply of goods or services, for rental to others, or for administrative purposes; and (b) are expected to be used during more than one period.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-URIDate 2020-01-01

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