Due to Trust Account, Short-term Borrowings and Long-term Debt (Summary of Due to Trust Account Transactions) (Detail) - JPY (¥) ¥ in Millions	Mar. 31, 2026	Mar. 31, 2025
Debt Disclosure [Abstract]
Amount outstanding at end of fiscal year	¥ 1,776,344	¥ 3,762,641
Weighted average interest rate on outstanding balance at end of fiscal year	0.26%	0.10%

Amount of excess cash funds of individual trust accounts which were placed in the trust account. It is similar to short-term funding, including demand deposits and other overnight funds purchased.

No definition available.

Name:	mufg_DueToTrustAccount
Namespace Prefix:	mufg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant