XML 59 R49.htm IDEA: XBRL DOCUMENT
v3.23.3

Allowance for Credit Losses and Credit Quality of Loans, Summary (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 30, 2023 | Sep. 30, 2023 | Dec. 31, 2022 | Jun. 30, 2023 | Mar. 31, 2023 | Sep. 30, 2022 | Jun. 30, 2022 | Dec. 31, 2021
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses | $ 114,601 | $ 114,601 | $ 100,800 | $ 100,400 |  | $ 96,800 | $ 93,600 | $ 92,000
Percentage of allowance of credit losses | 1.19% | 1.19% | 1.24% |  |  |  |  |
Recorded total loans | $ 9,667,375 | $ 9,667,375 | $ 8,150,147 |  |  |  |  |
Loans purchased with credit deterioration |  |  | 0 |  |  |  |  |
Allowance for credit losses on loans purchased | 17 | 17 | 3,200 |  |  |  |  |
Salisbury Bank [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Loans purchased with credit deterioration | 219,500 | 219,500 |  |  |  |  |  |
Allowance for credit losses on loans purchased | 5,800 | 5,800 |  |  |  |  |  |
Allowance for credit losses at acquisition | 14,500 |  |  |  |  |  |  |
Acquisition-related provision for credit losses | 8,800 | 8,800 |  |  |  |  |  |
Salisbury Bank [Member] | PCD [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses at acquisition | 5,800 |  |  |  |  |  |  |
Salisbury Bank [Member] | Non-PCD [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses at acquisition | 8,800 |  |  |  |  |  |  |
ASU 2022-02 [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses | 114,601 | 114,601 | 100,152 |  |  |  |  |
Loans [Member] | Cumulative Effect, Period of Adoption, Adjustment [Member] | ASU 2022-02 [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses |  |  | (600) |  |  |  |  |
Accrued Interest Receivable [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses | 0 | 0 | 0 |  |  |  |  |
AIR on loans | $ 32,500 | $ 32,500 | $ 25,000 |  |  |  |  |
Financing Receivable, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration] | Other Assets | Other Assets | Other Assets |  |  |  |  |
PPP [Member] | Maximum [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Recorded total loans |  |  |  |  | $ 1,000 |  |  |
Residential [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses | $ 20,607 | $ 20,607 |  | 15,554 |  | 15,534 | 16,302 | 18,806
Recorded total loans | 2,611,692 | 2,611,692 | $ 2,114,495 |  |  |  |  |
Amount of loans purchased |  | $ 2,400 | $ 11,500 |  |  |  |  |
Premium on loans purchased |  | 7.01% | 1.53% |  |  |  |  |
Residential [Member] | ASU 2022-02 [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses | 20,607 | $ 20,607 | $ 14,539 |  |  |  |  |
Consumer Loans [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses | 47,274 | 47,274 |  | $ 47,883 |  | $ 48,310 | $ 44,940 | $ 44,253
Recorded total loans | 2,195,382 | 2,195,382 | 2,099,087 |  |  |  |  |
Amount of loans purchased |  |  | 50,100 |  |  |  |  |
Consumer Loans [Member] | ASU 2022-02 [Member] |  |  |  |  |  |  |  |
Allowance for Credit Losses [Abstract] |  |  |  |  |  |  |  |
Allowance for credit losses | $ 47,274 | $ 47,274 | $ 50,951 |  |  |  |  |

X
- Definition Amount of allowance for credit loss at acquisition date of financing receivable purchased. + References No definition available. + Details
Name: | nbtb_FinancingReceivableAllowanceForCreditLossAtAcquisitionDate
Namespace Prefix: | nbtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of contractually required allowance for credit losses at acquisition-related provision for credit losses. + References No definition available. + Details
Name: | nbtb_FinancingReceivableAllowanceForCreditLossesAcquisitionRelatedProvision
Namespace Prefix: | nbtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of loans purchased with credit deterioration during the period. + References No definition available. + Details
Name: | nbtb_LoansPurchasedWithCreditDeterioration
Namespace Prefix: | nbtb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The premium percentage on loans purchased. + References No definition available. + Details
Name: | nbtb_PremiumOnLoansPurchased
Namespace Prefix: | nbtb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of allowance for credit loss to total financing receivable outstanding. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (1) -Publisher SEC + Details
Name: | srt_FinancingReceivableAllowanceForCreditLossToOutstandingPercent
Namespace Prefix: | srt_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Reserve for loans impairments recorded after acquisition as a result of current information and events which result in it being probable that estimated cash flows will be less than previously expected or because actual cash flows are less than cash flows previously expected. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 15 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481906/310-30-15-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (b)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481696/310-30-50-2 + Details
Name: | us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesAllowanceForLoanLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after allowance for credit loss, of accrued interest on financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3A -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-3A + Details
Name: | us-gaap_FinancingReceivableAccruedInterestAfterAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Indicates line item in statement of financial position that includes accrued interest, after allowance for credit loss, on financing receivable. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3A -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-3A + Details
Name: | us-gaap_FinancingReceivableAccruedInterestAfterAllowanceForCreditLossStatementOfFinancialPositionExtensibleList
Namespace Prefix: | us-gaap_
Data Type: | enum2:enumerationSetItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (1) -Publisher SEC Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (3) -Publisher SEC Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (c) -Publisher SEC Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(7)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 11B -Subparagraph (c)(1) -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-11B Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 80 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479294/326-20-55-80 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479294/326-20-55-79 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479344/326-20-45-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(3)(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (1) -Publisher SEC Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (2) -Publisher SEC Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Name Regulation S-K (SK) -Number 229 -Section 1404 -Paragraph (a) -Publisher SEC Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-14 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 7A -SubTopic 10 -Topic 310 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-7A Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-5 + Details
Name: | us-gaap_NotesReceivableGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The cash outflow for the purchase of loan receivable arising from the financing of goods and services. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147482740/230-10-45-13 + Details
Name: | us-gaap_PaymentsToAcquireLoansReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

X
- Details
Name: | us-gaap_CreditLossStatusAxis=us-gaap_FinancialAssetAcquiredWithCreditDeteriorationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditLossStatusAxis=us-gaap_FinancialAssetAcquiredAndNoCreditDeteriorationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate202202Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_LoansReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CumulativeEffectPeriodOfAdoptionAxis=srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_AccruedIncomeReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nbtb_PaycheckProtectionProgramLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |