v3.26.1
Provisions - Movements by Class of Provisions (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disclosure of other provisions [line items]    
Beginning balance ¥ 333,301 ¥ 231,319
Additional provisions 66,063 136,493
Amounts used (22,227) (26,892)
Unused amounts reversed (5,456) (5,315)
Amortization of discount and effect of change in discount rate (16,694) (2,148)
Others 76 (156)
Ending balance 355,063 333,301
Provision for interest repayment [member]    
Disclosure of other provisions [line items]    
Beginning balance 209,659 120,864
Additional provisions 112,407
Amounts used (15,384) (21,320)
Unused amounts reversed
Amortization of discount and effect of change in discount rate (16,855) (2,292)
Others
Ending balance 177,420 209,659
Other provisions [member]    
Disclosure of other provisions [line items]    
Beginning balance 123,642 110,455
Additional provisions 66,063 24,086
Amounts used (6,843) (5,572)
Unused amounts reversed (5,456) (5,315)
Amortization of discount and effect of change in discount rate 161 144
Others 76 (156)
Ending balance ¥ 177,643 ¥ 123,642