Derivative instruments and hedging activities - Summary of changes in fair value of hedging instruments related to cash flow hedges recorded in accumulated other comprehensive income (Detail) - Cash Flow Hedges [member] - JPY (¥)
¥ in Millions

12 Months Ended

Mar. 31, 2026

Mar. 31, 2025

Disclosure Of Information About Change In Fair Value Of Hedging Instruments Related To Cash Flow Hedges Recorded In Accumulated Other Comprehensive Income [Line Items]

Balance at the beginning

¥ 15,470

¥ 19,765

Changes in fair value of hedging instruments recognized in other comprehensive income

(7,416)

(5,384)

Reclassification adjustments to profit(loss) for the year

^[1],[2]

2,829

433

1,203

656

Balance at the end

12,086

15,470

Foreign Exchange Contract [Member]

Disclosure Of Information About Change In Fair Value Of Hedging Instruments Related To Cash Flow Hedges Recorded In Accumulated Other Comprehensive Income [Line Items]

Balance at the beginning

75

(1,720)

Changes in fair value of hedging instruments recognized in other comprehensive income

(10,377)

(6,238)

Reclassification adjustments to profit(loss) for the year

^[1],[2]

9,695

8,824

331

(791)

Balance at the end

(276)

75

Interest Rate Contracts [Member]

Disclosure Of Information About Change In Fair Value Of Hedging Instruments Related To Cash Flow Hedges Recorded In Accumulated Other Comprehensive Income [Line Items]

Balance at the beginning

15,395

21,485

Changes in fair value of hedging instruments recognized in other comprehensive income

2,961

854

Reclassification adjustments to profit(loss) for the year

^[1],[2]

(6,866)

(8,391)

872

1,447

Balance at the end

¥ 12,362

¥ 15,395

[1]	For the fiscal years ended March 31, 2025 and 2026, hedge ineffectiveness recognized in profit or loss was not material.
[2]	In the consolidated statements of income, the amount reclassified to profit (loss) is included in sales for hedges of foreign exchange contracts and in financial expenses for hedges of interest rate contracts.