v3.25.2
Insurance contracts in the financial services segment - Summary of remaining coverage and liabilities for incurred claims (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Insurance service expenses    
Insurance finance expenses (income) ¥ 30,155 ¥ 57,995
Other (1,334) 76
Insurance contracts issued remaining coverage and incurred claim [member]    
Disclosure of reconciliation of changes in insurance contracts by remaining coverage and incurred claims [line items]    
Insurance contract assets, Beginning (56,975) (60,751)
Insurance contract liabilities, Beginning 13,094,339 12,510,030
Net amounts, Beginning 13,037,364 12,449,279
Insurance revenue (622,959) (586,115)
Insurance service expenses    
Incurred claims and other insurance service expenses 298,177 273,088
Amortization of insurance acquisition cash flows 134,818 124,518
Changes in liabilities for incurred claims 5,661 5,008
Losses and reversals of losses on onerous contracts 14,276 4,592
Total insurance service expenses 452,932 407,206
Insurance service result (170,027) (178,909)
Insurance finance expenses (income) (634,805) 247,205
Total amounts recognized in comprehensive income (804,832) 68,296
Premiums received 2,056,493 1,886,124
Insurance acquisition cash flows (167,299) (153,410)
Claims and other insurance service expenses paid (1,298,150) (1,212,518)
Total cash flows 591,044 520,196
Other (653) (407)
Insurance contract assets, Ending (47,715) (56,975)
Insurance contracts liabilities, Ending 12,870,638 13,094,339
Net amounts, Ending 12,822,923 13,037,364
Net liabilities or assets for remaining coverage excluding loss component [member] | Insurance contracts issued remaining coverage and incurred claim [member]    
Disclosure of reconciliation of changes in insurance contracts by remaining coverage and incurred claims [line items]    
Insurance contract assets, Beginning (90,377) (93,283)
Insurance contract liabilities, Beginning 12,900,023 12,331,738
Net amounts, Beginning 12,809,646 12,238,455
Insurance revenue (622,959) (586,115)
Insurance service expenses    
Amortization of insurance acquisition cash flows 134,818 124,518
Total insurance service expenses 134,818 124,518
Insurance service result (488,141) (461,597)
Insurance finance expenses (income) (631,892) 244,793
Total amounts recognized in comprehensive income (1,120,033) (216,804)
Investment component excluded from insurance revenue and insurance service expenses (992,966) (944,520)
Premiums received 2,056,493 1,886,124
Insurance acquisition cash flows (167,299) (153,410)
Total cash flows 1,889,194 1,732,714
Other (68) (199)
Insurance contract assets, Ending (81,537) (90,377)
Insurance contracts liabilities, Ending 12,667,310 12,900,023
Net amounts, Ending 12,585,773 12,809,646
Loss component [member] | Insurance contracts issued remaining coverage and incurred claim [member]    
Disclosure of reconciliation of changes in insurance contracts by remaining coverage and incurred claims [line items]    
Insurance contract liabilities, Beginning 55,333 51,840
Net amounts, Beginning 55,333 51,840
Insurance service expenses    
Incurred claims and other insurance service expenses (5,882) (3,721)
Losses and reversals of losses on onerous contracts 14,276 4,592
Total insurance service expenses 8,394 871
Insurance service result 8,394 871
Insurance finance expenses (income) (498) 2,663
Total amounts recognized in comprehensive income 7,896 3,534
Other (46) (41)
Insurance contract assets, Ending 2  
Insurance contracts liabilities, Ending 63,181 55,333
Net amounts, Ending 63,183 55,333
Liabilities for incurred claims [member] | Insurance contracts issued remaining coverage and incurred claim [member]    
Disclosure of reconciliation of changes in insurance contracts by remaining coverage and incurred claims [line items]    
Insurance contract assets, Beginning 33,402 32,532
Insurance contract liabilities, Beginning 138,983 126,452
Net amounts, Beginning 172,385 158,984
Insurance service expenses    
Incurred claims and other insurance service expenses 304,059 276,809
Changes in liabilities for incurred claims 5,661 5,008
Total insurance service expenses 309,720 281,817
Insurance service result 309,720 281,817
Insurance finance expenses (income) (2,415) (251)
Total amounts recognized in comprehensive income 307,305 281,566
Investment component excluded from insurance revenue and insurance service expenses 992,966 944,520
Claims and other insurance service expenses paid (1,298,150) (1,212,518)
Total cash flows (1,298,150) (1,212,518)
Other (539) (167)
Insurance contract assets, Ending 33,820 33,402
Insurance contracts liabilities, Ending 140,147 138,983
Net amounts, Ending ¥ 173,967 ¥ 172,385