Annual report [Section 13 and 15(d), not S-K Item 405]

GOODWILL AND INTANGIBLE ASSETS (Narrative) (Details)

v3.25.4
GOODWILL AND INTANGIBLE ASSETS (Narrative) (Details) - USD ($)
$ in Thousands
 6 Months Ended 12 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Apr. 01, 2025
Apr. 01, 2024
Finite-Lived Intangible Assets [Line Items]            
Goodwill $ 1,733,287 $ 1,733,287 $ 1,214,053      
Intangible Assets $ 315,544 315,544 84,563      
Impairment of goodwill or intangible assets   0        
Intangible assets, amortization expense   $ 59,668 19,307 $ 8,781    
Minimum [Member]            
Finite-Lived Intangible Assets [Line Items]            
Intangible assets, amortization period (years) 4 years 4 years        
Maximum [Member]            
Finite-Lived Intangible Assets [Line Items]            
Intangible assets, amortization period (years) 15 years 15 years        
American National            
Finite-Lived Intangible Assets [Line Items]            
Goodwill $ 288,800 $ 288,800 $ 288,842     $ 288,842
American National | Wholesale Banking            
Finite-Lived Intangible Assets [Line Items]            
Goodwill 210,800 210,800        
American National | Consumer Banking            
Finite-Lived Intangible Assets [Line Items]            
Goodwill 78,000 78,000        
Sandy Spring            
Finite-Lived Intangible Assets [Line Items]            
Goodwill 519,234 519,234     $ 519,234  
Goodwill, measurement period adjustments 22,400          
Sandy Spring | Wholesale Banking            
Finite-Lived Intangible Assets [Line Items]            
Goodwill 404,900 404,900        
Sandy Spring | Consumer Banking            
Finite-Lived Intangible Assets [Line Items]            
Goodwill $ 114,300 $ 114,300