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

SEGMENT REPORTING AND REVENUE (Operating Segment Results) (Details)

v3.25.4
SEGMENT REPORTING AND REVENUE (Operating Segment Results) (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
USD ($)
segment
Dec. 31, 2024
USD ($)
Dec. 31, 2023
USD ($)
Apr. 01, 2025
USD ($)
Apr. 01, 2024
USD ($)
Disaggregation of Revenue [Line Items]          
Number of operating segments | segment 2        
Interest and dividend income $ 1,821,487 $ 1,227,535 $ 954,450    
Interest expense 666,574 528,996 343,437    
Net interest income 1,154,913 698,539 611,013    
Provision for credit losses 141,788 50,089 31,618    
Net interest income after provision for credit losses 1,013,125 648,450 579,395    
Noninterest income 219,436 118,878 90,877    
Noninterest expenses 895,570 507,534 430,371    
Income (loss) before income taxes 336,991 259,794 239,901    
LHFI, net of unearned income 27,796,167 18,470,621      
Goodwill 1,733,287 1,214,053      
Deposits 30,471,636 20,397,619      
American National          
Disaggregation of Revenue [Line Items]          
Goodwill 288,800 288,842     $ 288,842
Sandy Spring          
Disaggregation of Revenue [Line Items]          
Goodwill 519,234     $ 519,234  
Wholesale Banking | American National          
Disaggregation of Revenue [Line Items]          
Goodwill 210,800        
Wholesale Banking | Sandy Spring          
Disaggregation of Revenue [Line Items]          
Goodwill 404,900        
Consumer Banking | American National          
Disaggregation of Revenue [Line Items]          
Goodwill 78,000        
Consumer Banking | Sandy Spring          
Disaggregation of Revenue [Line Items]          
Goodwill 114,300        
Operating segments | Wholesale Banking          
Disaggregation of Revenue [Line Items]          
Interest and dividend income 1,636,974 1,222,101 934,242    
Interest expense 1,052,754 844,408 663,257    
Net interest income 584,220 377,693 270,985    
Provision for credit losses 107,659 40,072 34,229    
Net interest income after provision for credit losses 476,561 337,621 236,756    
Noninterest income 96,565 44,811 36,791    
Noninterest expenses 327,406 194,704 164,283    
Income (loss) before income taxes 245,720 187,728 109,264    
LHFI, net of unearned income 23,179,687 15,514,640      
Goodwill 1,254,979 850,035      
Deposits 11,339,236 7,193,403      
Operating segments | Wholesale Banking | American National          
Disaggregation of Revenue [Line Items]          
Goodwill   210,800      
Operating segments | Wholesale Banking | Sandy Spring          
Disaggregation of Revenue [Line Items]          
Goodwill 404,900        
Operating segments | Consumer Banking          
Disaggregation of Revenue [Line Items]          
Interest and dividend income 902,327 619,855 452,388    
Interest expense 483,906 318,839 198,542    
Net interest income 418,421 301,016 253,846    
Provision for credit losses 34,110 10,029 (2,616)    
Net interest income after provision for credit losses 384,311 290,987 256,462    
Noninterest income 72,537 59,344 51,347    
Noninterest expenses 382,896 250,178 228,374    
Income (loss) before income taxes 73,952 100,153 79,435    
LHFI, net of unearned income 5,317,949 3,085,207      
Goodwill 478,308 364,018      
Deposits 17,820,026 11,899,197      
Operating segments | Consumer Banking | American National          
Disaggregation of Revenue [Line Items]          
Goodwill   78,000      
Operating segments | Consumer Banking | Sandy Spring          
Disaggregation of Revenue [Line Items]          
Goodwill 114,300        
Corporate Other          
Disaggregation of Revenue [Line Items]          
Interest and dividend income (717,814) (614,421) (432,180)    
Interest expense (870,086) (634,251) (518,362)    
Net interest income 152,272 19,830 86,182    
Provision for credit losses 19 (12) 5    
Net interest income after provision for credit losses 152,253 19,842 86,177    
Noninterest income 50,334 14,723 2,739    
Noninterest expenses 185,268 62,652 37,714    
Income (loss) before income taxes 17,319 (28,087) 51,202    
LHFI, net of unearned income (701,469) (129,226)      
Goodwill 0 0      
Deposits $ 1,312,374 $ 1,305,019      
Corporate Other | Strategic cost saving initiatives          
Disaggregation of Revenue [Line Items]          
Noninterest expenses     12,600    
Corporate Other | Strategic cost saving initiatives | Other expenses          
Disaggregation of Revenue [Line Items]          
Noninterest expenses     9,800    
Corporate Other | Strategic cost saving initiatives | Salaries and benefits          
Disaggregation of Revenue [Line Items]          
Noninterest expenses     $ 2,800