Financial investments, Restructuring agreement of Abengoa (Details) - mi	6 Months Ended
Jun. 30, 2021	Dec. 31, 2020
Ten West Link [Member]
Restructuring Agreement [Abstract]
Percentage of interest acquired	12.50%
Length of transmission lines	114
Rioglass [Member]
Restructuring Agreement [Abstract]
Percentage of interest acquired		15.12%

The percentage of voting equity interests acquired in a business combination. [Refer: Business combinations [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2020-01-01
-Paragraph B64
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2020-en-r&anchor=para_B64_c&doctype=Appendix&subtype=B
-URIDate 2020-01-01

Name:	ifrs-full_PercentageOfVotingEquityInterestsAcquired
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant