Other Financial Assets - Summary of Fair Value of Investments in Equity Instruments Designated at Fair Value Through Other Comprehensive Income (Detail) - JPY (¥) ¥ in Millions	12 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Financial assets measured at fair value through other comprehensive income [abstract]
Total fair value	¥ 277,319	¥ 681,271
Accumulated other comprehensive income, net	¥ 217,516	¥ 512,976

The fair value at the date of the derecognition of investments in equity instruments that the entity has designated at fair value through other comprehensive income. [Refer: Investments in equity instruments designated at fair value through other comprehensive income [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2025-01-01
-Paragraph 11B
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2025-en-r&anchor=para_11B_b&doctype=Standard
-URIDate 2025-03-27

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