Cash and Deposits with Banks - Additional Information (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Cash and cash equivalents [abstract]
Reserves funds required to be maintained by the SMBC Group	¥ 1,983,987	¥ 2,102,543	¥ 1,948,949

The amount of reserve that is kept in deposit at a central bank to fulfil regulatory reserve requirements.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 112
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_112_c&doctype=Standard
-URIDate 2023-03-23

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