v3.26.1
Schedule H, Line 4i – Schedule of Assets (Held At End of Year) (Details) - EBP 003 - USD ($)
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
EBP, Schedule of Asset Held for Investment [Line Items]    
Entity tax identification number 72-1192928  
Plan number 003  
EBP, Asset Held for Investment $ 127,079,753  
Minimum    
EBP, Schedule of Asset Held for Investment [Line Items]    
Note receivable from participants, maturity term 0 years  
Note receivable from participants, interest rate 4.25%  
Maximum    
EBP, Schedule of Asset Held for Investment [Line Items]    
Note receivable from participants, maturity term 12 years  
Note receivable from participants, interest rate 9.50%  
Mutual funds    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value $ 87,256,435  
Notes receivable from participants 1,852,266  
Origin Bancorp, Inc. (“Company”) stock    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value $ 37,971,052  
Origin Bancorp, Inc. Common Stock, number of shares (in shares) 1,009,600 1,080,965
Origin Bancorp, Inc. Common Stock, par value (in dollars per share) $ 5.00  
Investment, Identifier [Axis]: Mutual Funds | Dodge & Cox | Dodge & Cox Income    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value $ 6,329,435  
Investment, Identifier [Axis]: Mutual Funds | Dodge & Cox | Dodge & Cox Stock    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 6,899,988  
Investment, Identifier [Axis]: Mutual Funds | Federated Securities Corporation | Government Obligations Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 1,257,014  
Investment, Identifier [Axis]: Mutual Funds | MFS Investment Management | MFS Growth R6 Fund    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 8,420,528  
Investment, Identifier [Axis]: Mutual Funds | MFS Investment Management | MFS INTL Diversification R6 FD    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 2,148,366  
Investment, Identifier [Axis]: Mutual Funds | MFS Investment Management | MFS New Discovery R6    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 109,866  
Investment, Identifier [Axis]: Mutual Funds | PIMCO | PIMCO Income Institutional    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 2,539,706  
Investment, Identifier [Axis]: Mutual Funds | T. Rowe Price | T. Rowe Price Dividend Growth    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 5,250,376  
Investment, Identifier [Axis]: Mutual Funds | T.Rowe Price | T. Rowe Price MD-CP GR I FD    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 198,307  
Investment, Identifier [Axis]: Mutual Funds | TIAA Investments | TIAA-CREF Lifestyle Aggressive Growth Institutional    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 1,430,875  
Investment, Identifier [Axis]: Mutual Funds | TIAA Investments | TIAA-CREF Lifestyle Conservative Institutional    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 14,160,403  
Investment, Identifier [Axis]: Mutual Funds | TIAA Investments | TIAA-CREF Lifestyle Growth Institutional    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 2,169,748  
Investment, Identifier [Axis]: Mutual Funds | TIAA Investments | TIAA-CREF Lifestyle Income Institutional    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 112,899  
Investment, Identifier [Axis]: Mutual Funds | TIAA Investments | TIAA-CREF Lifestyle Moderate Institutional    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 2,997,856  
Investment, Identifier [Axis]: Mutual Funds | The American Funds | American Funds New World R6    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 1,867,727  
Investment, Identifier [Axis]: Mutual Funds | Vanguard | Vanguard 500 Index Admiral    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 15,255,541  
Investment, Identifier [Axis]: Mutual Funds | Vanguard | Vanguard International Growth Admiral    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 2,499,752  
Investment, Identifier [Axis]: Mutual Funds | Vanguard | Vanguard Mid-cap Index Admiral    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 4,973,977  
Investment, Identifier [Axis]: Mutual Funds | Vanguard | Vanguard Real Estate Index Admiral    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 625,983  
Investment, Identifier [Axis]: Mutual Funds | Vanguard | Vanguard Short Term Federal Admiral    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 2,996,832  
Investment, Identifier [Axis]: Mutual Funds | Vanguard | Vanguard Small-cap Index Admiral    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value 3,353,749  
Investment, Identifier [Axis]: Mutual Funds | Vanguard | Vanguard Total International Stock Index Admiral    
EBP, Schedule of Asset Held for Investment [Line Items]    
Current value $ 1,657,507