v3.26.1
Income Taxes - Schedule of unrecognized tax benefits (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Income Tax Disclosure [Abstract]      
Balance at beginning of year ¥ 48,462 ¥ 41,437 ¥ 34,763
Increases based on tax positions related to the current period 8,551 6,791 5,076
Increases based on tax positions related to the prior periods 17 866 608
Decreases related to lapse of the applicable statute of limitations (1,957)   (3,812)
Exchange rate fluctuations 3,433 (632) 4,802
Balance at end of year ¥ 58,506 ¥ 48,462 ¥ 41,437