Employee benefits - Summary of Defined Contribution Expenses (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Japanese Plans [Member]
Disclosure of Detailed Information About Defined Contribution Plans Explanatory [Line Items]
Total defined contribution expenses	¥ 11,137	¥ 10,992
Foreign Plans [Member]
Disclosure of Detailed Information About Defined Contribution Plans Explanatory [Line Items]
Total defined contribution expenses	¥ 11,154	¥ 9,639

The amount of post-employment benefit expense relating to defined contribution plans. Defined contribution plans are post-employment benefit plans under which an entity pays fixed contributions into a separate entity (a fund) and will have no legal or constructive obligation to pay further contributions if the fund does not hold sufficient assets to pay all employee benefits relating to employee service in the current and prior periods.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2021-01-01
-Paragraph 53
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2021-en-r&anchor=para_53&doctype=Standard
-URIDate 2021-03-24

Name:	ifrs-full_PostemploymentBenefitExpenseDefinedContributionPlans
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration