v3.26.1
Business, Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details)
3 Months Ended 6 Months Ended
Jul. 22, 2026
$ / shares
Apr. 01, 2025
USD ($)
Jun. 30, 2026
USD ($)
$ / shares
shares
Mar. 31, 2026
$ / shares
shares
Jun. 30, 2025
USD ($)
$ / shares
shares
Mar. 31, 2025
$ / shares
shares
Jun. 30, 2026
USD ($)
segment
$ / shares
shares
Jun. 30, 2025
USD ($)
$ / shares
shares
Jan. 31, 2026
USD ($)
Class of Stock [Line Items]                  
Redemption of senior notes             $ 0 $ 60,000,000  
Number of operating segments | segment             1    
Repurchase of common stock - Class A             $ 35,067,000 10,000,000  
Treasury stock, value     $ 0   $ 0   0 $ 0  
Impairment of equity investment     0       1,800,000    
Equity method investments, fintech     $ 0       0    
Dividends declared (in dollars per share) | $ / shares     $ 0.09 $ 0.09 $ 0.09 $ 0.09      
Initial ACL on acquired PSLs     $ 1,900,000       $ 2,360,000    
Subsequent Event                  
Class of Stock [Line Items]                  
Dividends declared (in dollars per share) | $ / shares $ 0.09                
Common Stock                  
Class of Stock [Line Items]                  
Repurchase of common stock (in shares) | shares     690,000 859,493 275,666 215,427      
Class A Common Stock | Common Stock                  
Class of Stock [Line Items]                  
Repurchase of common stock (in shares) | shares     690,000   275,666   1,549,493 491,093  
Treasury stock acquired (in dollars per share) | $ / shares     $ 23.29   $ 18.14   $ 22.44 $ 20.36  
Repurchase of common stock - Class A     $ 16,400,000   $ 5,000,000.0   $ 35,100,000 $ 10,000,000.0  
2026 Repurchase Program | Class A Common Stock                  
Class of Stock [Line Items]                  
Stock repurchase program, authorized amount                 $ 40,000,000
Amerant Bank, N.A                  
Class of Stock [Line Items]                  
Ownership percentage of subsidiary     100.00%       100.00%    
5.75% Senior Notes due 2025 | Senior notes                  
Class of Stock [Line Items]                  
Redemption of senior notes   $ 60,000,000.0              
Interest rate, stated percentage   5.75%              
Contractual call price   100.00%              
Extinguishment of debt, amount   $ 60,900,000