v3.26.1
BUSINESS COMBINATION - Additional Information (Details) - USD ($)
$ in Thousands
3 Months Ended 12 Months Ended
Jan. 01, 2026
Nov. 01, 2025
Jun. 23, 2025
Feb. 29, 2024
Dec. 31, 2021
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
Business Combination [Line Items]                  
Assets           $ 22,779,815   $ 21,129,379  
Net loans and leases           13,311,125   13,237,583  
Deposits           17,918,722   16,421,842  
Business Combination, Recognized Liability Assumed, Liability             $ 0    
Business Combination, Bargain Purchase, Gain Recognized, Amount           8,892 0    
Less: Allowance for credit losses           183,716 $ 155,482 186,487 $ 156,791
BankFinancial                  
Business Combination [Line Items]                  
Assets           1,400,000      
Deposits               $ 1,300,000  
Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares 5,980,878                
Business Combination, Consideration Transferred, Equity Interest $ 149,648                
Cash consideration 6                
Business Combination, Recognized Asset Acquired, Asset 1,408,726                
Business Combination, Recognized Liability Assumed, Liability 1,250,180         1,250,180      
Goodwill   $ 9,000              
Business combination, Consideration Transferred, Equity interest Issued Ratio               0.48  
Business Combination, Bargain Purchase, Gain Recognized, Amount 8,892         8,892      
Financing Receivable, Purchased with Credit Deterioration, Amount at Par Value 4,000                
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date 800                
Financing Receivable, Purchased with Credit Deterioration, Amount at Purchase Price 3,000                
Business Combination, Consideration Transferred 149,654                
Less: Allowance for credit losses $ 2,800             $ 2,829  
Westfield Bank                  
Business Combination [Line Items]                  
Assets           2,100,000      
Deposits           1,900,000      
Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares     2,753,094            
Business Combination, Consideration Transferred, Equity Interest     $ 64,400   $ 64,450        
Cash consideration     260,000 $ 260,000          
Payments for Merger Related Costs           5,300   $ 5,800  
Business Combination, Recognized Asset Acquired, Asset   2,128,552              
Business Combination, Recognized Liability Assumed, Liability           $ 156      
Goodwill   91,887              
Business Combination, Price of Acquisition, Expected     $ 324,400            
Financing Receivable, Purchased with Credit Deterioration, Amount at Par Value   32,000              
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date   3,000              
Financing Receivable, Purchased with Credit Deterioration, Amount at Purchase Price   27,400              
Less: Allowance for credit losses   $ 23,700