Income Taxes (Tax Effects of Temporary Differences and Carryforwards Giving Rise to Deferred Tax Assets and Liabilities) (Parenthetical) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2024	Mar. 31, 2023
Income Taxes [Line Items]
Deferred Tax Assets, Other	¥ 156,516	¥ 103,210
Related To Changes In Foreign Exchange Rate [Member]
Income Taxes [Line Items]
Deferred Tax Assets, Other	¥ 95,551	¥ 52,262

Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-6

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-8

Name:	us-gaap_DeferredTaxAssetsOther
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant