Impairment losses - Joint operations (Details)	12 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Cornerstone Telecommunications Infrastructure Limited
Disclosure of joint operations [line items]
Proportion of ownership interest in joint operation	50.00%	50.00%

The proportion of ownership interest in a joint operation attributable to the entity. [Refer: Joint operations [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2021-01-01
-Paragraph 21
-Subparagraph a
-Clause iv
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=12&code=ifrs-tx-2021-en-r&anchor=para_21_a_iv&doctype=Standard
-URIDate 2021-03-24

Name:	ifrs-full_ProportionOfOwnershipInterestInJointOperation
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration