XML 91 R76.htm IDEA: XBRL DOCUMENT v3.3.1.900

Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 23, 2015	Dec. 31, 2014
Commitments and Contingent Liabilities [Abstract]
Percentage of the Company's loans secured by real estate	58.00%
Guarantor Obligations [Line Items]
Loans serviced by the Company for unrelated third parties	$ 616,100		$ 626,000
Mortgage servicing rights	$ 1,100		1,500
Federal Reserve Bank Requirement [Abstract]
Federal Reserve Bank maintenance period	14 days
Average reserve at Federal Reserve Bank for maintenance period		$ 55,800
Unused lines of Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	$ 252,953		214,175
Commitment to Extend Credits, Primarily Variable Rate [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	1,062,425		972,912
Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	$ 31,503		35,244
Obligation instrument term	5 years
Commercial Letters of Credit [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	$ 11,332		22,486
Loans Sold with Recourse [Member]
Guarantor Obligations [Line Items]
Commitments - maximum potential obligation	$ 25,122		$ 23,351

X

- Definition

For banks and other depository institutions, the calculated average reserve balance outstanding for the specific period as of the Balance Sheet date. Includes noninterest bearing balances with the Federal Reserve Banks.

+ References

No definition available.

+ Details

Name:	nbtb_AverageReserveBalancesWithFederalReserveBank
Namespace Prefix:	nbtb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- References

No definition available.

+ Details

Name:	nbtb_FederalReserveBankRequirementAbstract
Namespace Prefix:	nbtb_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Describe the approximate period of the guarantee or each group of similar guarantees.

+ References

No definition available.

+ Details

Name:	nbtb_GuarantorObligationsPeriod
Namespace Prefix:	nbtb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The dollar amount of principal for mortgage loans being serviced for others.

+ References

No definition available.

+ Details

Name:	nbtb_LoansServicedByCompanyForUnrelatedThirdParties
Namespace Prefix:	nbtb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Specific period of time established required to maintain reserve balances with the Federal Reserve Bank expressed in days.

+ References

No definition available.

+ Details

Name:	nbtb_MaintenancePeriodBasisFederalReserveBank
Namespace Prefix:	nbtb_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The percentage of the Company's loans secured by real estate.

+ References

No definition available.

+ Details

Name:	nbtb_PercentageOfCompanysLoansSecuredByRealEstate
Namespace Prefix:	nbtb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- References

No definition available.

+ Details

Name:	us-gaap_CommitmentsAndContingenciesDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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_GuaranteeObligationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Aggregate amount of servicing assets that are subsequently measured at fair value and servicing assets that are subsequently measured using the amortization method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6469459&loc=d3e122501-111745

+ Details

Name:	us-gaap_ServicingAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_UnusedLinesOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=nbtb_CommitmentToExtendCreditsCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_FinancialStandbyLetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_GuaranteeObligationsByNatureAxis=nbtb_LoansSoldWithRecourseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: