v3.25.2
Financial risk management - Summary of Maturity Analysis for Non-Derivative and Derivative Financial Liabilities (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2025
Mar. 31, 2024
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Financial liabilities ¥ 10,964,623 ¥ 10,326,710
Deposits from customers in the banking business 4,281,915 3,870,349
Bonds 688,245 554,986
Borrowings 2,971,250 3,013,803
Loan commitments 27,564 50,965
Derivative liabilities 155,095 29,557
Guarantee deposits received 45,017 44,864
Redeemable noncontrolling interests 53,750 54,389
Lease liabilities 712,098 671,899
Derivative Contracts - Net Settled    
Paid 155,095 28,220
Derivative Contracts Gross Settled    
Received 0 49,187
Paid 0 50,524
Deposits from customers in the banking business [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Financial liabilities 4,243,962 3,845,607
Bonds [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Financial liabilities 664,390 544,078
Borrowings [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Financial liabilities 2,934,386 2,972,629
Loan commitments [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Financial liabilities 0 0
Derivative Liabilities [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Financial liabilities 154,526 29,287
Guarantee deposits received [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Financial liabilities 45,017 44,864
Redeemable non-controlling interests [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Financial liabilities 52,963 54,028
Gross carrying amount [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Lease liabilities 599,470 571,726
Within 1Year [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Deposits from customers in the banking business 4,006,600 3,687,051
Bonds 114,299 42,236
Borrowings 1,934,886 1,909,097
Loan commitments 27,564 50,965
Derivative liabilities 21,479 23,465
Guarantee deposits received 31,866 31,479
Redeemable noncontrolling interests 10,912  
Lease liabilities 115,608 106,505
Derivative Contracts - Net Settled    
Paid 21,479 22,128
Derivative Contracts Gross Settled    
Received 0 49,187
Paid 0 50,524
1 Year to 2 Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Deposits from customers in the banking business 96,834 22,043
Bonds 128,972 112,112
Borrowings 264,847 84,525
Derivative liabilities 121,611 1,179
Guarantee deposits received 100 135
Redeemable noncontrolling interests 21,588 14,794
Lease liabilities 107,197 96,090
Derivative Contracts - Net Settled    
Paid 121,611 1,179
Derivative Contracts Gross Settled    
Received 0  
Paid 0  
2 Years to 3 Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Deposits from customers in the banking business 11,141 11,422
Bonds 103,488 126,786
Borrowings 233,755 259,511
Derivative liabilities 3,173 1,178
Guarantee deposits received 21 9
Redeemable noncontrolling interests 4,447 25,740
Lease liabilities 94,233 85,917
Derivative Contracts - Net Settled    
Paid 3,173 1,178
Derivative Contracts Gross Settled    
Received 0  
Paid 0  
3 Years to 4 Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Deposits from customers in the banking business 2,692 2,728
Bonds 93,160 101,302
Borrowings 157,629 231,829
Derivative liabilities 2,693 1,145
Guarantee deposits received 7 24
Redeemable noncontrolling interests 3,405 99
Lease liabilities 75,125 68,624
Derivative Contracts - Net Settled    
Paid 2,693 1,145
Derivative Contracts Gross Settled    
Received 0  
Paid 0  
4 Years to 5 Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Deposits from customers in the banking business 10,596 3,069
Bonds 162,927 80,974
Borrowings 21,521 156,945
Derivative liabilities 2,340 953
Guarantee deposits received 6 10
Redeemable noncontrolling interests 2,287 5,292
Lease liabilities 67,715 57,850
Derivative Contracts - Net Settled    
Paid 2,340 953
Derivative Contracts Gross Settled    
Received 0  
Paid 0  
5+ Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Deposits from customers in the banking business 154,052 144,036
Bonds 85,399 91,576
Borrowings 358,612 371,896
Derivative liabilities 3,799 1,637
Guarantee deposits received 13,017 13,207
Redeemable noncontrolling interests 11,111 8,464
Derivative Contracts - Net Settled    
Paid 3,799 1,637
Derivative Contracts Gross Settled    
Received 0  
Paid 0  
5 Years to 6 Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Lease liabilities 52,376 51,240
6 Years to 7 Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Lease liabilities 42,763 47,630
7 years to 8 Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Lease liabilities 34,114 37,279
8 Years to 9 Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Lease liabilities 25,860 29,390
9 Years to 10 Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Lease liabilities 21,529 21,954
10+ Years [member]    
Disclosure Of Maturity Analysis For Financial Liabilities [Line Items]    
Lease liabilities ¥ 75,578 ¥ 69,420