v3.26.1
Employee Benefits - Additional Information (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2027
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of defined benefit plans [line items]        
Payroll expenses   ¥ 5,081,959 ¥ 4,794,497 ¥ 4,385,112
Japanese plans [Member] | Scenario forecasts [Member]        
Disclosure of defined benefit plans [line items]        
Estimatedcontributions expected to be paid in next annual reporting  ¥ 34,336      
Foreign plans [Member] | Scenario forecasts [Member]        
Disclosure of defined benefit plans [line items]        
Estimatedcontributions expected to be paid in next annual reporting  ¥ 18,488