v3.26.1
Fair Value Measurements - Schedule of Plan's Assets at Fair Value by Level Within Fair Value Hierarchy (Details) - EBP 001 - USD ($)
Dec. 31, 2025
Dec. 31, 2024
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value $ 376,680,505 $ 351,751,871
Prosperity Bancshares, Inc. Common Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 38,813,766 40,006,459
Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 79,774,967 73,721,521
Collective Investment Trusts    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 243,037,548 220,268,306
Money Market Account    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 15,054,224 17,755,585
Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 357,482,089 338,463,449
Level 1 | Prosperity Bancshares, Inc. Common Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 38,813,766 40,006,459
Level 1 | Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 79,774,967 73,721,521
Level 1 | Collective Investment Trusts    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 223,839,132 206,979,884
Level 1 | Money Market Account    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 15,054,224 17,755,585
Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 19,198,416 13,288,422
Level 2 | Prosperity Bancshares, Inc. Common Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 0 0
Level 2 | Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 0 0
Level 2 | Collective Investment Trusts    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 19,198,416 13,288,422
Level 2 | Money Market Account    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 0 0
Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 0 0
Level 3 | Prosperity Bancshares, Inc. Common Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 0 0
Level 3 | Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 0 0
Level 3 | Collective Investment Trusts    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value 0 0
Level 3 | Money Market Account    
EBP, Investment, Fair Value and NAV [Line Items]    
TOTAL INVESTMENTS, at Fair Value $ 0 $ 0