v3.26.1
BORROWED FUNDS - Subordinated and Junior Subordinated Borrowings (Narrative) (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2026
Dec. 31, 2024
Dec. 31, 2025
Nov. 26, 2019
BORROWED FUNDS        
Net loans $ 3,550,933   $ 3,571,807  
Maximum borrowing capacity 451,500      
Asset Pledged as Collateral | FHLB stock        
BORROWED FUNDS        
Net loans $ 867,700   $ 740,700  
Financial guarantee        
BORROWED FUNDS        
Interest rate margin 2.79%      
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember      
NHTB Capital Trust II and NHTB Capital Trust III | Financial guarantee        
BORROWED FUNDS        
Debentures issued by variable interest entities $ 20,600      
Subordinated borrowings private placement        
BORROWED FUNDS        
Principal amount of debt issued       $ 40,000
Fixed interest rate       4.63%
Interest rate margin 3.27%      
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember      
Repayments of subordinated debt   $ 20,000    
Outstanding subordinated debt $ 20,000      
Acquired subordinated notes        
BORROWED FUNDS        
Principal amount of debt issued 13,000      
Fair value $ 11,200      
Interest rate margin 4.82%      
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember      
Effective interest rate 4.875%