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Description of Business (Policies) | 9 Months Ended
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Sep. 30, 2025
Description of Business [Abstract] |
Nature of Operations | NBT Bancorp Inc. is a registered financial holding company incorporated in the state of Delaware in 1986, with its principal headquarters located in Norwich, New York. The principal assets of NBT Bancorp Inc. consist of all of the outstanding shares of common stock of its subsidiaries, including: NBT Bank, National Association (the “Bank”), NBT Financial Services, Inc. (“NBT Financial”), NBT Holdings, Inc. (“NBT Holdings”), CNBF Capital Trust I, NBT Statutory Trust I, NBT Statutory Trust II, Alliance Financial Capital Trust I, Alliance Financial Capital Trust II and Evans Capital Trust I (collectively, the “Trusts”). The principal sources of revenue for NBT Bancorp Inc. are the management fees and dividends it receives from the Bank, NBT Financial and NBT Holdings. Collectively, NBT Bancorp Inc. and its subsidiaries are referred to herein as (the “Company”). The Company’s business, primarily conducted through the Bank, consists of providing commercial banking, retail banking and wealth management services primarily to customers in its market area, which includes upstate New York, northeastern Pennsylvania, southern New Hampshire, western Massachusetts, Vermont, southern Maine and central and northwestern Connecticut. The Company has been, and intends to continue to be, a community-oriented financial institution offering a variety of financial services. The Company’s business philosophy is to operate as a community bank with local decision-making, providing a broad array of banking and financial services to retail, commercial and municipal customers. On May 2, 2025, the Company completed the acquisition of Evans Bancorp, Inc. (“Evans”). Evans was headquartered in Williamsville, New York. Evans Bank, National Association (“Evans Bank”), was a federally-chartered national banking association operating 18 banking locations in Western New York.

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