v3.19.3
Document and Entity Information - shares
9 Months Ended
Sep. 30, 2019
Nov. 12, 2019
Entity Registrant Name Amerant Bancorp Inc.  
Entity Central Index Key 0001734342  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Document Type 10-Q  
Document Period End Date Sep. 30, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Amendment Flag false  
Entity Small Business false  
Entity Emerging Growth Company true  
Entity Ex Transition Period false  
Entity Shell Company false  
Entity Current Reporting Status Yes  
Class A common stock    
Entity Common Stock, Shares Outstanding   28,988,579
Class B common stock    
Entity Common Stock, Shares Outstanding   14,218,596