v3.26.1
Loans - Impaired Nonaccrual Loans Information And Interest Income Recognized On Nonaccrual Loans (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Financing Receivable, Nonaccrual [Line Items]    
Nonaccrual loans with an allowance [1] ¥ 798,000 ¥ 1,003,000
Nonaccrual loans without an allowance [1] 102,000 58,000
Total nonaccrual loans [1] 899,000 1,062,000
Interest income recognized [2] 22,000 20,000
Domestic    
Financing Receivable, Nonaccrual [Line Items]    
Nonaccrual loans with an allowance 659 911,000 [1]
Nonaccrual loans without an allowance 53 54,000 [1]
Total nonaccrual loans 712 965,000 [1]
Interest income recognized 12 15,000 [2]
Domestic | Retail | Housing Loan    
Financing Receivable, Nonaccrual [Line Items]    
Nonaccrual loans with an allowance [1] 17,000 18,000
Nonaccrual loans without an allowance [1] 11,000 12,000
Total nonaccrual loans [1] 28,000 30,000
Interest income recognized [2] 1,000 1,000
Domestic | Retail | Other    
Financing Receivable, Nonaccrual [Line Items]    
Nonaccrual loans with an allowance [1] 24,000 26,000
Nonaccrual loans without an allowance [1] 17,000 17,000
Total nonaccrual loans [1] 41,000 43,000
Interest income recognized [2] 1,000 1,000
Domestic | Large companies | Corporate    
Financing Receivable, Nonaccrual [Line Items]    
Nonaccrual loans with an allowance [1] 542,000 788,000
Nonaccrual loans without an allowance [1] 16,000 12,000
Total nonaccrual loans [1] 558,000 800,000
Interest income recognized [2] 9,000 12,000
Domestic | Small and medium sized companies | Corporate    
Financing Receivable, Nonaccrual [Line Items]    
Nonaccrual loans with an allowance [1] 77,000 79,000
Nonaccrual loans without an allowance [1] 9,000 13,000
Total nonaccrual loans [1] 86,000 92,000
Interest income recognized [2] 2,000 1,000
Foreign    
Financing Receivable, Nonaccrual [Line Items]    
Nonaccrual loans with an allowance [1],[3] 138,000 92,000
Nonaccrual loans without an allowance [1],[3] 49,000 4,000
Total nonaccrual loans [1],[3] 187,000 96,000
Interest income recognized [2],[3] ¥ 10,000 ¥ 5,000
[1] Amounts represent the outstanding balances of nonaccrual loans. The MHFG Group’s policy for placing loans in nonaccrual status is consistent with the Group’s definition of nonaccrual loans.
[2] Amounts represent the amount of interest income on nonaccrual loans recognized on a cash basis and included in Interest income on loans in the consolidated statements of income.
[3] The majority of total foreign consist of corporate.