v3.26.1
Variable Interest Entities and Securitizations (Carrying Amounts and Classification of Assets and Liabilities on Consolidated Balance Sheets that Relate to Variable Interests in Significant Unconsolidated VIEs) (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Assets on consolidated balance sheets      
Trading account assets ¥ 48,696,032 ¥ 37,598,099  
Loans 105,078,764 98,440,989  
Total assets 294,895,707 276,741,152 ¥ 272,173,200
Liabilities on the MHFG Group's balance sheets and maximum exposure to loss related to unconsolidated VIEs:      
Trading account liabilities 28,802,058 21,207,668  
Total liabilities 283,417,654 266,191,227  
Maximum exposure to loss 2,070,000 1,521,000  
Unconsolidated VIEs      
Assets on consolidated balance sheets      
Total assets 7,955,000 5,823,000  
Mizuho Financial Group, Inc. | Unconsolidated VIEs      
Assets on consolidated balance sheets      
Trading account assets 99,000 93,000  
Investments 1,514,000 863,000  
Loans 203,000 254,000  
Total assets 1,815,000 1,210,000  
Liabilities on the MHFG Group's balance sheets and maximum exposure to loss related to unconsolidated VIEs:      
Trading account liabilities 3,000 3,000  
Total liabilities 3,000 3,000  
Maximum exposure to loss [1] ¥ 2,070,000 ¥ 1,521,000  
[1] This represents the maximum amount the Group could possibly be required to record in its consolidated statements of income associated with on-balance-sheet exposures and off-balance-sheet liabilities such as undrawn commitments.