v3.26.1
Deferred Income Tax - Amounts of Deductible Temporary Differences and Tax Losses Carried Forward by Expiration Date (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Deductible temporary differences ¥ 27,650 ¥ 313,645
Total deductible temporary differences and tax losses carried forward [1] 480,102 755,056
Tax losses carried forward which will expire in 1 year [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward 34,664 14,653
Tax losses carried forward which will expire in 2 years [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward 1,073 34,369
Tax losses carried forward which will expire in 3 years [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward 113,237 2,540
Tax losses carried forward which will expire in 4 years [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward 29,676 114,096
Tax losses carried forward which will expire in 5 years [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward 24,742 46,323
Tax losses carried forward which will expire in 6 years [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward 28,238 40,580
Tax losses carried forward which will expire in 7 years [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward 34,365 40,090
Tax losses carried forward which will expire in 8 years [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward 43,150 34,383
Tax losses carried forward which will expire in 9 years [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward 57,614 43,006
Tax losses carried forward which will expire in 10 years and thereafter [member]    
Disclosure of temporary difference, unused tax losses and unused tax credits which no deferred tax assets were recognized [line items]    
Tax losses carried forward ¥ 85,693 ¥ 71,371
[1] Under the group aggregation system, the Company and its wholly-owned domestic subsidiaries recognized deferred tax assets relating to deductible temporary differences and tax losses carried forward on a consolidated basis for Japanese national corporation tax purposes and on a stand-alone basis for Japanese local corporation tax purposes. There are deductible temporary differences and tax losses carried forward on which deferred tax assets are recognized for Japanese national corporation tax purposes, but on which no deferred tax assets are recognized for Japanese local corporation tax purposes. These deductible temporary differences and tax losses carried forward amounted to ¥12,581 million and ¥304,322 million at March 31, 2026 and 2025, respectively.