XML 89 R75.htm IDEA: XBRL DOCUMENT v3.20.4

Allowance for Credit Losses and Credit Quality of Loans, Average Recorded Investments on Loans Specifically Evaluated for Impairment and Interest Income Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	$ 19,733	$ 20,429
Interest income recognized	891	901
Originated Loans [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	19,733	20,429
Interest income recognized	891	901
Originated Loans [Member] | Commercial Loans [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	4,642	5,549
Interest income recognized	148	155
Originated Loans [Member] | Commercial Loans [Member] | C&I [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	242	453
Interest income recognized	1	1
Originated Loans [Member] | Commercial Loans [Member] | CRE [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	3,311	4,078
Interest income recognized	123	128
Originated Loans [Member] | Commercial Loans [Member] | Business Banking [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	1,089	1,018
Interest income recognized	24	26
Originated Loans [Member] | Consumer Loans [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	7,586	8,101
Interest income recognized	393	441
Originated Loans [Member] | Consumer Loans [Member] | Indirect Auto [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	192	179
Interest income recognized	10	10
Originated Loans [Member] | Consumer Loans [Member] | Direct [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	7,387	7,922
Interest income recognized	382	431
Originated Loans [Member] | Consumer Loans [Member] | Specialty Lending [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	7	0
Interest income recognized	1	0
Originated Loans [Member] | Residential Real Estate [Member]
Average Recorded Investment and Interest Income Recognized [Abstract]
Average recorded investment	7,505	6,779
Interest income recognized	$ 350	$ 305

X

- References

No definition available.

+ Details

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

X

- Definition

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

+ Details

Name:	us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

+ Details

Name:	us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=nbtb_OriginatedLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nbtb_CommercialAndIndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_RealEstateLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nbtb_SmallBusinessFinancingReceivableMember
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:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nbtb_IndirectAutoFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nbtb_DirectFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=nbtb_SpecialtyLendingMember
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: