XML 83 R68.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Junior Subordinated Debt (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 USD ($) Trust Period
Debt Instrument [Line Items] |
Number of statutory business trusts included in the Trusts | Trust | 5
Minimum assets for bank holding companies to be subject to the same capital requirements as insured depository institutions | $ 500,000
CNBF Capital Trust I Debenture [Member] |
Debt Instrument [Line Items] |
Number of wholly owned Delaware statutory business trusts | 1
CNBF Capital Trust I Debenture [Member] | LIBOR [Member] |
Debt Instrument [Line Items] |
Issuance Date | Aug. 01, 1999
Trust Preferred Securities Outstanding | $ 18,000
Variable rate basis | 3-month LIBOR
Basis spread on variable rate | 2.75%
Trust Preferred Debt Owed To Trust | $ 18,720
Final Maturity Date | Aug. 01, 2029
NBT Statutory Trust I Debenture [Member] | LIBOR [Member] |
Debt Instrument [Line Items] |
Issuance Date | Nov. 01, 2005
Trust Preferred Securities Outstanding | $ 5,000
Variable rate basis | 3-month LIBOR
Basis spread on variable rate | 1.40%
Trust Preferred Debt Owed To Trust | $ 5,155
Final Maturity Date | Dec. 01, 2035
NBT Statutory Trust II Debenture [Member] | LIBOR [Member] |
Debt Instrument [Line Items] |
Issuance Date | Feb. 01, 2006
Trust Preferred Securities Outstanding | $ 50,000
Variable rate basis | 3-month LIBOR
Basis spread on variable rate | 1.40%
Trust Preferred Debt Owed To Trust | $ 51,547
Final Maturity Date | Mar. 01, 2036
Alliance Financial Capital Trust I [Member] | LIBOR [Member] |
Debt Instrument [Line Items] |
Issuance Date | Dec. 01, 2003
Trust Preferred Securities Outstanding | $ 10,000
Variable rate basis | 3-month LIBOR
Basis spread on variable rate | 2.85%
Trust Preferred Debt Owed To Trust | $ 10,310
Final Maturity Date | Jan. 01, 2034
Alliance Financial Capital Trust II [Member] | LIBOR [Member] |
Debt Instrument [Line Items] |
Issuance Date | Sep. 01, 2006
Trust Preferred Securities Outstanding | $ 15,000
Variable rate basis | 3-month LIBOR
Basis spread on variable rate | 1.65%
Trust Preferred Debt Owed To Trust | $ 15,464
Final Maturity Date | Sep. 01, 2036
NBT Bancorp Inc [Member] |
Debt Instrument [Line Items] |
Trust equity method investment | $ 1,000
Alliance Financial Capital [Member] |
Debt Instrument [Line Items] |
Number of wholly owned Delaware statutory business trusts | 2
Trusts [Member] |
Debt Instrument [Line Items] |
Trust Preferred Securities Outstanding | $ 98,000
Trust Preferred Debt Owed To Trust | 101,000
Trust equity method investment | $ 3,200
Debentures period semi-annual deferral periods | Period | 10
Trust preferred securities included in Tier I capital | $ 97,000

X
- Definition Amount of trust preferred debt owed to the trust at the balance sheet date. + References No definition available. + Details
Name: | nbtb_DebtInstrumentAmountOwedToTrust
Namespace Prefix: | nbtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition For an issue of Subordinated Debentures, maximum distribution deferral period (payments of interest). + References No definition available. + Details
Name: | nbtb_DistributionDeferralPeriodSubordinatedDebentures
Namespace Prefix: | nbtb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The minimum assets for bank holding companies to be subject to the same capital requirements as insured depository institutions under the Dodd-Frank Act. + References No definition available. + Details
Name: | nbtb_MinimumAssetsForBankHoldingCompaniesToBeSubjectToSameCapitalRequirementsAsInsuredDepositoryInstitutions
Namespace Prefix: | nbtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The number of statutory business trusts issued junior subordinated deferrable interest debentures. + References No definition available. + Details
Name: | nbtb_NumberOfStatutoryBusinessTrusts
Namespace Prefix: | nbtb_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the number of statutory business trusts included in the Trusts. + References No definition available. + Details
Name: | nbtb_NumberOfStatutoryBusinessTrustsIncludedInTrusts
Namespace Prefix: | nbtb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Tier 1 Risk Based Capital as defined in the regulations that includes only trust preferred securities. + References No definition available. + Details
Name: | nbtb_TrustPreferredSecuritiesIncludedTierOneCapital
Namespace Prefix: | nbtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentDescriptionOfVariableRateBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Date the debt instrument was issued, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentIssuanceDate1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDateRangeEnd1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35755396&loc=d3e33749-111570 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_EquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentAxis=nbtb_CnbfCapitalTrustIDebentureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=nbtb_NbtStatutoryTrustIDebentureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=nbtb_NbtStatutoryTrustIiDebentureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=nbtb_AllianceFinancialCapitalTrustIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=nbtb_AllianceFinancialCapitalTrustIiMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=us-gaap_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=nbtb_AllianceFinancialCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=nbtb_CombinedTrustsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |