Contingent Liabilities (Narrative) (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2022
Mar. 31, 2021
Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]      
Allowance for repayment of excess interest ¥ 21,120 ¥ 24,943  
Provision (reversal) for repayment of excess interest recognized on Equity in earnings of equity method investee ¥ 23,332 ¥ 0 ¥ 7,800