Property, plant and equipment - Narrative (Details)	12 Months Ended
Mar. 31, 2024
Gas distribution \| Weighted average \| US
Disclosure of detailed information about property, plant and equipment [line items]
Useful economic life, property, plant and equipment	53 years

The useful life, measured as period of time, used for property, plant and equipment. [Refer: Property, plant and equipment]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2023-01-01
-Paragraph 73
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=16&code=ifrs-tx-2023-en-r&anchor=para_73_c&doctype=Standard
-URIDate 2023-03-23

Name:	ifrs-full_UsefulLifeMeasuredAsPeriodOfTimePropertyPlantAndEquipment
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration