v3.25.2
Regulatory Capital Requirements (Narrative) (Detail)
¥ in Millions
Apr. 01, 2024
Mar. 31, 2025
JPY (¥)
guideline
capitalRatio
Approach
Mar. 31, 2024
JPY (¥)
Mar. 31, 2023
Nov. 11, 2022
Dec. 31, 2017
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]            
Number of methodologies/guidelines | guideline   2        
Number of regulatory capital ratios | capitalRatio   3        
Percentage of G-SIB leverage ratio buffer to G-SIB capital surcharge, effective on prior and current period       0.75%    
Percentage of increase of G-SIB leverage ratio buffer to G-SIB capital surcharge, effective on and after April 1, 2024 0.0005          
Consolidated, MUFG            
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]            
Minimum Common Equity Tier 1 capital ratio   0.0866 0.0866      
Tier 1 leverage ratio   0.0395 0.0375      
Basel III            
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]            
Number of approaches | Approach   3        
FSA's requirements applicable to Japanese banking institutions            
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]            
Minimum Common Equity Tier 1 capital ratio       0.0450    
Capital conservation buffer   2.50% 2.50%      
G-SIB surcharge   1.50% 1.50%      
Tier 1 leverage ratio 0.0315         0.0300
Countercyclical buffer   0.16% 0.16%      
Percentage of G-SIB leverage ratio buffer to G-SIB capital surcharge, effective on prior and current period       50.00% 50.00% 50.00%
Basel III for Security Companies in Japan            
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]            
Minimum capital ratio required for financial Instruments firms to maintain by Financial Instruments and Exchange Act and related ordinance   120.00%        
Minimum capital ratio requirement for financial instruments firms which will call for regulatory reporting   140.00%        
Minimum capital ratio requirement for financial instrument firms which may lead to a suspension of all or part of the business for a period of time and cancellation of a registration   100.00%        
Basel III for Security Companies in Japan | Stand-alone, Mitsubishi UFJ Morgan Stanley Securities            
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]            
Amount of capital accounts less certain fixed assets   ¥ 564,169 ¥ 537,309      
Percentage of capital accounts to the total amounts equivalent to market, counterparty credit and operational risks   300.70% 305.20%      
Basel III for Security Companies in Japan | Consolidated, MUFG            
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]            
Amount of capital accounts less certain fixed assets   ¥ 564,266