Financial instruments - Summary of Equity Instruments Measured at Fair Value Through Other Comprehensive Income (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2022	Mar. 31, 2021	Apr. 01, 2020
Marketable Equity Instruments [Member]
Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [line items]
Equity instruments measured at fair value through other comprehensive income	¥ 106,499	¥ 241,577	¥ 10,432
Nonmarketable Equity Instruments [Member]
Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [line items]
Equity instruments measured at fair value through other comprehensive income	205,509	104,541	47,233
Equity Instruments [Member]
Disclosure of fair value of investments in equity instruments designated at fair value through other comprehensive income [line items]
Equity instruments measured at fair value through other comprehensive income	¥ 312,008	¥ 346,118	¥ 57,665

The amount of investments in equity instruments that the entity has designated at fair value through other comprehensive income. [Refer: At fair value [member]; Other comprehensive income]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2021-01-01
-Paragraph 11A
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_11A_c&doctype=Standard
-URIDate 2021-03-24

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2021-01-01
-Paragraph 8
-Subparagraph h
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2021-en-r&anchor=para_8_h&doctype=Standard
-URIDate 2021-03-24

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant