v3.26.3
Credit Quality of Financial Assets and the Allowance for Credit Losses - Summary of Past-Due Financial Assets (Detail) - JPY (¥)
¥ in Millions
Sep. 30, 2026
Mar. 31, 2026
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables ¥ 2,487,406 ¥ 2,527,163
Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 98,097 109,156
30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 37,516 52,250
90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 60,581 56,906
Consumer borrowers    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 72,264 79,093
Consumer borrowers | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 13,503 13,708
Consumer borrowers | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,094 3,941
Consumer borrowers | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 11,409 9,767
Consumer borrowers | Real estate loans    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 33,638 38,119
Consumer borrowers | Real estate loans | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 11,286 11,146
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 800 2,252
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 10,486 8,894
Consumer borrowers | Other    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 38,626 40,974
Consumer borrowers | Other | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 2,217 2,562
Consumer borrowers | Other | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 1,294 1,689
Consumer borrowers | Other | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 923 873
Corporate borrowers    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 1,159,688 1,179,343
Corporate borrowers | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 28,053 36,988
Corporate borrowers | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 10,834 16,246
Corporate borrowers | 90 days or more past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 17,219 20,742
Corporate borrowers | Non-recourse Loans | Japan    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 48,927 81,084
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   200,308
Corporate borrowers | Non-recourse Loans | The Americas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables   11,478
Corporate borrowers | Non-recourse Loans | Overseas    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 133,844  
Corporate borrowers | Non-recourse Loans | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 3,941  
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   6,022
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 0  
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   5,456
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 3,941  
Corporate borrowers | Other than non-recourse loans | Real estate companies | Japan    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 128,660 118,727
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 309 292
Corporate borrowers | Other than non-recourse loans | Real estate companies | Overseas    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 91,163 61,853
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 2,455 2,544
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 309 292
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 677 363
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 0
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 1,778 2,181
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | Japan    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 197,666 191,880
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 2,930 2,983
Corporate borrowers | Other than non-recourse loans | Commercial, industrial and other companies | Overseas    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 559,428 525,491
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 18,418 19,691
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 2,774 2,442
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 7,074 7,127
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 156 541
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 11,344 12,564
Loans to Equity Method Investees    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 24,615 21,236
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 1,230,839 1,247,491
Net investment in leases | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 56,541 58,460
Net investment in leases | Japan    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 610,041 619,333
Net investment in leases | Japan | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 6,159 6,154
Net investment in leases | Overseas    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 620,798 628,158
Net investment in leases | Overseas | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 50,382 52,306
Net investment in leases | 30-89 days past-due | Past-due financing assets    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Total financing receivables 24,588 32,063
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 2,274 2,234
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 22,314 29,829
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 31,953 26,397
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 3,885 3,920
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 ¥ 28,068 ¥ 22,477