v3.26.1
Fair Value Measurements
 12 Months Ended
Dec. 31, 2025
NBT Bancorp Inc. 401(k) and Employee Stock Ownership Plan [Member]  
Fair Value Measurements [Abstract]  
Fair Value Measurements
3.
Fair Value Measurements
 
The following table presents the financial instruments recorded at fair value on a recurring basis by the Plan as of December 31, 2025 and 2024:
 
 
                             
Description
 
December 31, 2025
 
Level 1
 
Level 2
 
Level 3
Mutual funds
  $ 363,169,532    $ 363,169,532    $ -    $ -  
Common stock of NBT Bancorp Inc.
    30,074,182      30,074,182        -        -  
Stable value fund
    17,933,465      17,933,465        -        -  
Cash and money market funds
    31,988      31,988        -        -  
Total
  $ 411,209,167    $ 411,209,167    $ -    $ -  
 
                         
Description   December 31, 2024     Level 1     Level 2     Level 3  
Mutual funds
 $ 307,131,380   $ 307,131,380   $ -    $ -  
Common stock of NBT Bancorp Inc.
   35,226,305     35,226,305       -        -  
Stable value fund
   18,539,578     18,539,578       -        -  
Cash and money market funds
   86,728     86,728       -        -  
Total
 $ 360,983,991   $ 360,983,991   $ -    $ -  
The stable value fund consists of the Federated Capital Preservation Fund (“the Fund”), which primarily holds guaranteed investment contracts (“GICs”) and synthetic guaranteed investment contracts (“synthetic GICs”). GICs represent deposits which guarantee a stated interest rate for the term of the contracts. The crediting rate of security-backed contracts will track current market yields on a trailing basis. The rate reset allows the contract value to converge with the fair value of the underlying portfolio over time, assuming the portfolio continues to earn the current yield for a period of time equal to the current portfolio duration. The fair value of GICs is determined based on the present value of the contract's expected cash flows, discounted by current market interest rates for like duration and like quality investments. Synthetic GICs are portfolios of securities (debt securities or open end registered investment companies) owned by the Fund with wrap contracts that guarantee a fixed or variable rate for the term of the contracts.