v3.26.1
Fair Value Measurements - Summary of Plan's Assets Measured at Fair Value on a Recurring Basis (Details) - EBP 001 - USD ($)
Dec. 31, 2025
Dec. 31, 2024
EBP, Master Trust [Line Items]    
Investments, at fair value $ 957,000,119  
Investments, at fair value 957,000,119 $ 707,526,594
Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   777,597,721
Mutual Funds    
EBP, Master Trust [Line Items]    
Investments, at fair value 785,957,162  
Mutual Funds | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   569,017,347
Money Market Fund    
EBP, Master Trust [Line Items]    
Investments, at fair value 32,491,794  
Money Market Fund | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   29,916,843
UMB Company Stock    
EBP, Master Trust [Line Items]    
Investments, at fair value 21,348,783  
UMB Company Stock | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   91,095,797
Collective Investment Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value 117,202,380  
Collective Investment Trust | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   87,567,734
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Mutual Funds    
EBP, Master Trust [Line Items]    
Investments, at fair value 785,957,162  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Mutual Funds | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   569,017,347
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Money Market Fund    
EBP, Master Trust [Line Items]    
Investments, at fair value 32,491,794  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Money Market Fund | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   29,916,843
Fair Value, Inputs, Level 1, Level 2, and Level 3 | UMB Company Stock    
EBP, Master Trust [Line Items]    
Investments, at fair value 21,348,783  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | UMB Company Stock | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   91,095,797
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Total Assets in the Fair Value Hierarchy    
EBP, Master Trust [Line Items]    
Investments, at fair value 839,797,739  
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Total Assets in the Fair Value Hierarchy | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   690,029,987
Level 1 | Mutual Funds    
EBP, Master Trust [Line Items]    
Investments, at fair value 785,957,162  
Level 1 | Mutual Funds | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   569,017,347
Level 1 | Money Market Fund    
EBP, Master Trust [Line Items]    
Investments, at fair value 32,491,794  
Level 1 | Money Market Fund | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   29,916,843
Level 1 | UMB Company Stock    
EBP, Master Trust [Line Items]    
Investments, at fair value 21,348,783  
Level 1 | UMB Company Stock | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   91,095,797
Level 1 | Total Assets in the Fair Value Hierarchy    
EBP, Master Trust [Line Items]    
Investments, at fair value $ 839,797,739  
Level 1 | Total Assets in the Fair Value Hierarchy | Master Trust    
EBP, Master Trust [Line Items]    
Investments, at fair value   $ 690,029,987