XML 80 R65.htm IDEA: XBRL DOCUMENT
v3.3.1.900

LOANS, Troubled Debt Restructuring (TDR) (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 USD ($) Loan | Dec. 31, 2014 USD ($) Loan
Financing Receivable, Modifications [Line Items] |  |
Maximum threshold balance of TDRs included in general loan loss allocation and qualitative review | $ | $ 500 |
Number | 238 | 225
Amount | $ | $ 6,144 | $ 5,952
Loans modified in TDR during the year, number | 71 | 82
Loans modified in TDR during the year, amount | $ | $ 1,864 | $ 2,201
Number of non-Chapter 7 bankruptcy TDRs |  | 3
Nonaccrual [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 55 | 68
Amount | $ | $ 1,892 | $ 2,752
Accruing [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 183 | 157
Amount | $ | $ 4,252 | $ 3,200
Business Lending [Member] | Waiver of Payments for Period of Time [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Loans modified in TDR during the year, number |  | 2
Business Lending [Member] | Extension of Term [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Loans modified in TDR during the year, number |  | 1
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 91 | 86
Amount | $ | $ 3,958 | $ 3,862
Loans modified in TDR during the year, number | 21 | 22
Loans modified in TDR during the year, amount | $ | $ 1,374 | $ 949
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Nonaccrual [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 37 | 49
Amount | $ | $ 1,472 | $ 2,092
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Accruing [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 54 | 37
Amount | $ | $ 2,486 | $ 1,770
Commercial Portfolio Segment [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Minimum threshold amount of individual loans evaluated for impairment | $ | $ 500 |
Commercial Portfolio Segment [Member] | Business Lending [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 14 | 9
Amount | $ | $ 954 | $ 910
Loans modified in TDR during the year, number | 3 | 7
Loans modified in TDR during the year, amount | $ | $ 67 | $ 769
Commercial Portfolio Segment [Member] | Business Lending [Member] | Nonaccrual [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 8 | 6
Amount | $ | $ 217 | $ 442
Commercial Portfolio Segment [Member] | Business Lending [Member] | Accruing [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 6 | 3
Amount | $ | $ 737 | $ 468
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 77 | 79
Amount | $ | $ 691 | $ 615
Loans modified in TDR during the year, number | 35 | 33
Loans modified in TDR during the year, amount | $ | $ 349 | $ 312
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Nonaccrual [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 0 | 0
Amount | $ | $ 0 | $ 0
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Accruing [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 77 | 79
Amount | $ | $ 691 | $ 615
Consumer Portfolio Segment [Member] | Consumer Direct [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 32 | 25
Amount | $ | $ 37 | $ 69
Loans modified in TDR during the year, number | 6 | 14
Loans modified in TDR during the year, amount | $ | $ 11 | $ 26
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Nonaccrual [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 0 | 0
Amount | $ | $ 0 | $ 0
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Accruing [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 32 | 25
Amount | $ | $ 37 | $ 69
Consumer Portfolio Segment [Member] | Home Equity [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 24 | 26
Amount | $ | $ 504 | $ 496
Loans modified in TDR during the year, number | 6 | 6
Loans modified in TDR during the year, amount | $ | $ 63 | $ 145
Consumer Portfolio Segment [Member] | Home Equity [Member] | Nonaccrual [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 10 | 13
Amount | $ | $ 203 | $ 218
Consumer Portfolio Segment [Member] | Home Equity [Member] | Accruing [Member] |  |
Financing Receivable, Modifications [Line Items] |  |
Number | 14 | 13
Amount | $ | $ 301 | $ 278

X
- Definition Maximum threshold balance of financing receivables classified as a troubled debt restructuring that are collectively evaluated for impairment. + References No definition available. + Details
Name: | cbu_FinancingReceivableModificationsCollectivelyEvaluatedForImpairmentMaximumThreshold
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Refers to the number of non-Chapter 7 bankruptcy financing receivables that have been modified by troubled debt restructurings during the period. + References No definition available. + Details
Name: | cbu_FinancingReceivableModificationsNonChapter7BankruptcyTDRsNumberOfContracts
Namespace Prefix: | cbu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References No definition available. + Details
Name: | cbu_FinancingReceivableModificationsNumberOfContracts
Namespace Prefix: | cbu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The minimum threshold amount of loans which are individually evaluated for impairment. + References No definition available. + Details
Name: | cbu_MinimumThresholdAmountOfIndividualLoansEvaluatedForImpairment
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_FinancingReceivableModificationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Post-modification amount of investment in financing receivables modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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

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

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_PaymentDeferralMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
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_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialMortgageMember
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_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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