Commitments, contingencies and guarantees - Information on derivative contracts and standby letters of credit and other guarantees (Detail) - JPY (¥) ¥ in Millions		Mar. 31, 2020	Mar. 31, 2019
Derivative contracts [Member]
Guarantees [Line Items]
Carrying value	[1],[2]	¥ 7,197,647	¥ 4,315,743
Maximum potential payout /Notional total	[1],[2]	279,734,884	281,605,308
Standby letters of credit and other guarantees [Member]
Guarantees [Line Items]
Carrying value	[3]		80
Maximum potential payout /Notional total	[3]	¥ 2,351	¥ 5,764

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

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

[3] The amounts of collaterals held in connection with standby letters of credit and other guarantees as of March 31, 2019 and March 31, 2020 was ¥2,481 million and ¥nil, respectively.