v3.26.3
BORROWED FUNDS - Subordinated and Junior Subordinated Borrowings (Narrative) (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2026
Sep. 30, 2026
Dec. 31, 2024
Aug. 15, 2026
Dec. 31, 2025
Sep. 30, 2025
Nov. 26, 2019
BORROWED FUNDS              
Net loans $ 3,581,871 $ 3,581,871     $ 3,571,807    
Maximum borrowing capacity         259,100 $ 591,100  
Repayments of subordinated debt   20,000          
Asset Pledged as Collateral | FHLB stock              
BORROWED FUNDS              
Net loans 989,600 $ 989,600     $ 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 $ 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   $ 20,000        
Acquired subordinated notes              
BORROWED FUNDS              
Principal amount of debt issued 13,000 $ 13,000          
Fair value $ 11,200 $ 11,200          
Interest rate margin   4.82%          
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]   us-gaap:SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember          
Effective interest rate 4.875% 4.875%          
Redeemable amount       $ 13,000