v3.26.1
Mizuho Financial Group, Inc., parent company (Condensed statements of cash flows) (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Cash flows from operating activities:      
Net income ¥ 1,158,031 ¥ 593,393 ¥ 912,473
Net cash provided by operating activities (1,781,369) 59,044 (3,460,502)
Cash flows from investing activities:      
Net cash used in investing activities (11,806,403) (4,530,312) (3,679,457)
Cash flows from financing activities:      
Net change in short-term borrowings (2,763,358) 1,934,023 14,167
Proceeds from issuance of long-term debt 7,655,894 3,144,808 3,061,735
Repayment of long-term debt (2,548,148) (4,336,484) (2,956,548)
Purchases of treasury stock (404,325) (102,921) (3,384)
Net cash provided by financing activities 1,855,213 3,955,420 11,457,601
Net increase (decrease) in cash and cash equivalents (10,829,577) (677,064) 6,120,748
Cash and cash equivalents at beginning of fiscal year 73,435,979 74,113,043 67,992,295
Cash and cash equivalents at end of fiscal year 62,606,401 73,435,979 74,113,043
Parent Company      
Cash flows from operating activities:      
Net income 1,158,031 593,393 912,473
Adjustments and other (587,254) 61,316 (421,191)
Net cash provided by operating activities 570,776 654,709 491,282
Cash flows from investing activities:      
Purchases of Equity securities 0 (167,188) 0
Proceeds from sales of Equity securities 1 167,188 0
Net change in loans (974,616) (543,376) (130,719)
Purchases of investments in subsidiaries and affiliated companies (50,888) (65,212) (91,200)
Net change in other investing activities (4,651) (1,998) (9,983)
Net cash used in investing activities (1,030,153) (610,586) (231,902)
Cash flows from financing activities:      
Net change in short-term borrowings 285,000 (101,000) (179,000)
Proceeds from issuance of long-term debt 1,793,792 1,342,656 1,363,655
Repayment of long-term debt (849,176) (869,280) (1,232,936)
Purchases of treasury stock (402,628) (101,908) (2,478)
Dividends paid (368,704) (304,426) (234,787)
Net change in other financing activities 1,993 2,132 2,116
Net cash provided by financing activities 460,278 (31,826) (283,431)
Net increase (decrease) in cash and cash equivalents 901 12,298 (24,050)
Cash and cash equivalents at beginning of fiscal year 36,123 23,825 47,875
Cash and cash equivalents at end of fiscal year ¥ 37,024 ¥ 36,123 ¥ 23,825