XML 83 R68.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Acquisitions, Evans Bancorp, Inc. (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2024 USD ($) Location | Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($)
Acquisition of Evans Bancorp, Inc [Abstract] |  |  |
Acquisition expenses | $ 1,531 | $ 9,978 | $ 967
Evans Bancorp, Inc [Member] |  |  |
Acquisition of Evans Bancorp, Inc [Abstract] |  |  |
Assets of the acquiree | $ 2,190,000 |  |
Number of banking locations operated by acquiree | Location | 18 |  |
Share conversion rights | 0.91 |  |
Percentage of issued and outstanding shares represented | 75.00% |  |
Voting cast percentage | 96.00% |  |
Acquisition expenses | $ 1,500 |  |

X
- Definition The approximate value of the acquiree in a business combination stated in terms of the net assets of the acquiree. + References No definition available. + Details
Name: | nbtb_BusinessCombinationAssetValuationOfTheAcquiree
Namespace Prefix: | nbtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of common shares of the entity issuable to equity holders of the acquiree for each share of the acquiree to be converted. + References No definition available. + Details
Name: | nbtb_BusinessCombinationEquityInterestTransferredConversionRatio
Namespace Prefix: | nbtb_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of banking locations in which the bank operates. + References No definition available. + Details
Name: | nbtb_NumberOfBankingLocations
Namespace Prefix: | nbtb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage of votes cast to approve the merger. + References No definition available. + Details
Name: | nbtb_PercentageOfVotesCastToApproveMerger
Namespace Prefix: | nbtb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage total voting equity interest present at special shareholders meeting. + References No definition available. + Details
Name: | nbtb_VotingRightsPercentageRepresentedAtSpecialShareholdersMeeting
Namespace Prefix: | nbtb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 25 -Paragraph 23 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479405/805-10-25-23 + Details
Name: | us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_BusinessCombinationDescriptionAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=nbtb_EvansBancorpIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |