Commitments, contingencies and guarantees - Maturity information on derivative contracts and standby letters of credit and other guarantees (Detail) - JPY (¥) ¥ in Millions		Sep. 30, 2022	Mar. 31, 2022
Derivative contracts [Member]
Guarantees [Line Items]
Carrying value	[1],[2]	¥ 12,354,870	¥ 6,151,646
Maximum potential payout /Notional	[1],[2]	497,283,042	393,709,887
Derivative contracts [Member] | Less than 1 year [Member]
Guarantees [Line Items]
Maximum potential payout /Notional		111,702,087
Derivative contracts [Member] | 1 to 3 years [Member]
Guarantees [Line Items]
Maximum potential payout /Notional		159,340,394
Derivative contracts [Member] | 3 to 5 years [Member]
Guarantees [Line Items]
Maximum potential payout /Notional		76,103,006
Derivative contracts [Member] | More than 5 years [Member]
Guarantees [Line Items]
Maximum potential payout /Notional		150,137,555
Standby letters of credit and other guarantees [Member]
Guarantees [Line Items]
Carrying value	[3]
Maximum potential payout /Notional	[3]	1,521,994	¥ 1,698,193
Standby letters of credit and other guarantees [Member] | Less than 1 year [Member]
Guarantees [Line Items]
Maximum potential payout /Notional		1,507,633
Standby letters of credit and other guarantees [Member] | 1 to 3 years [Member]
Guarantees [Line Items]
Maximum potential payout /Notional		7,228
Standby letters of credit and other guarantees [Member] | 3 to 5 years [Member]
Guarantees [Line Items]
Maximum potential payout /Notional		5,572
Standby letters of credit and other guarantees [Member] | More than 5 years [Member]
Guarantees [Line Items]
Maximum potential payout /Notional		¥ 1,561

[1] Credit derivatives are disclosed in Note 3. “Derivative instruments and hedging activities” and are excluded from above.

[2] Derivative contracts primarily consist of equity, interest rate and foreign exchange contracts.

[3] Primarily related to a certain sponsored repo program where Nomura guarantees to a third party clearing house in relation to its clients’ payment obligations. Our credit exposures under this guarantee is minimized by obtaining collateral from clients at amount approximately the maximum potential payout under the guarantee.