v3.26.1
Credit Quality of Financial Assets and the Allowance for Credit Losses - Summary of Past-Due Financial Assets (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables ¥ 5,212,483 ¥ 5,056,614
Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 111,007 97,797
30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 53,051 34,490
90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 57,956 63,307
Consumer borrowers    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,133,067 2,067,900
Consumer borrowers | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 15,559 12,126
Consumer borrowers | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 4,742 4,481
Consumer borrowers | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 10,817 7,645
Consumer borrowers | Real estate loans    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,027,493 1,956,816
Consumer borrowers | Real estate loans | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 12,647 7,959
Consumer borrowers | Real estate loans | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,703 2,536
Consumer borrowers | Real estate loans | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 9,944 5,423
Consumer borrowers | Card loans    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 64,600 67,874
Consumer borrowers | Card loans | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 350 355
Consumer borrowers | Card loans | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 350 355
Consumer borrowers | Card loans | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 0 0
Consumer borrowers | Other    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 40,974 43,210
Consumer borrowers | Other | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,562 3,812
Consumer borrowers | Other | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 1,689 1,590
Consumer borrowers | Other | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 873 2,222
Corporate borrowers    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 1,810,689 1,689,281
Corporate borrowers | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 36,988 44,981
Corporate borrowers | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 16,246 9,896
Corporate borrowers | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 20,742 35,085
Corporate borrowers | Non-recourse Loans | Japan    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 343,121 301,477
Corporate borrowers | Non-recourse Loans | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 0 0
Corporate borrowers | Non-recourse Loans | The Americas    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables   86,724
Corporate borrowers | Non-recourse Loans | The Americas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables   5,837
Corporate borrowers | Non-recourse Loans | Overseas    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 200,308  
Corporate borrowers | Non-recourse Loans | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 11,478  
Corporate borrowers | Non-recourse Loans | 30-89 days past-due | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 0 0
Corporate borrowers | Non-recourse Loans | 30-89 days past-due | The Americas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables   2,141
Corporate borrowers | Non-recourse Loans | 30-89 days past-due | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 6,022  
Corporate borrowers | Non-recourse Loans | 90 days or more past-due | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 0 0
Corporate borrowers | Non-recourse Loans | 90 days or more past-due | The Americas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables   3,696
Corporate borrowers | Non-recourse Loans | 90 days or more past-due | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 5,456  
Corporate borrowers | Other than non-recourse loans | Real estate companies | Japan    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 461,006 415,666
Corporate borrowers | Other than non-recourse loans | Real estate companies | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 292 229
Corporate borrowers | Other than non-recourse loans | Real estate companies | Overseas    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 61,853 82,187
Corporate borrowers | Other than non-recourse loans | Real estate companies | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,544 2,455
Corporate borrowers | Other than non-recourse loans | Real estate companies | 30-89 days past-due | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 292 200
Corporate borrowers | Other than non-recourse loans | Real estate companies | 30-89 days past-due | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 363 36
Corporate borrowers | Other than non-recourse loans | Real estate companies | 90 days or more past-due | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 0 29
Corporate borrowers | Other than non-recourse loans | Real estate companies | 90 days or more past-due | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,181 2,419
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | Japan    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 218,910 225,900
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,983 2,512
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | Overseas    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 525,491 577,327
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 19,691 33,948
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | 30-89 days past-due | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,442 1,992
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | 30-89 days past-due | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 7,127 5,527
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | 90 days or more past-due | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 541 520
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | 90 days or more past-due | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 12,564 28,421
Loans to Equity Method Investees    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 21,236 132,053
Loans to Equity Method Investees | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 0 0
Loans to Equity Method Investees | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 0 0
Loans to Equity Method Investees | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 0 0
Net investment in leases    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 1,247,491 1,167,380
Net investment in leases | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 58,460 40,690
Net investment in leases | Japan    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 619,333 618,963
Net investment in leases | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 6,154 7,766
Net investment in leases | Overseas    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 628,158 548,417
Net investment in leases | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 52,306 32,924
Net investment in leases | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 32,063 20,113
Net investment in leases | 30-89 days past-due | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,234 3,851
Net investment in leases | 30-89 days past-due | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 29,829 16,262
Net investment in leases | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 26,397 20,577
Net investment in leases | 90 days or more past-due | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 3,920 3,915
Net investment in leases | 90 days or more past-due | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables ¥ 22,477 ¥ 16,662