v3.19.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2019
May 06, 2019
Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Trading Symbol OBNK  
Entity Registrant Name ORIGIN BANCORP, INC.  
Entity CIK 0001516912  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Emerging Growth Company true  
Entity Small Business false  
Entity Ex Transition Period true  
Entity Common Stock, Shares Outstanding   23,745,985