XML 69 R57.htm IDEA: XBRL DOCUMENT
v3.5.0.2

FAIR VALUE, Significant Unobservable Inputs (Details) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2016 | Dec. 31, 2015
Other Real Estate Owned [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair value | $ 2,060 | $ 2,088
Other Real Estate Owned [Member] | Fair Value of Collateral [Member] | Minimum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Estimated cost of disposal/market adjustment | 9.00% | 5.30%
Other Real Estate Owned [Member] | Fair Value of Collateral [Member] | Maximum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Estimated cost of disposal/market adjustment | 71.00% | 74.00%
Other Real Estate Owned [Member] | Fair Value of Collateral [Member] | Weighted Average [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Estimated cost of disposal/market adjustment | 23.40% | 27.70%
Impaired Loans [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair value | $ 769 | $ 1,765
Impaired Loans [Member] | Fair Value of Collateral [Member] | Minimum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Estimated cost of disposal/market adjustment | 15.00% | 9.00%
Impaired Loans [Member] | Fair Value of Collateral [Member] | Maximum [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Estimated cost of disposal/market adjustment | 17.60% | 20.00%
Impaired Loans [Member] | Fair Value of Collateral [Member] | Weighted Average [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Estimated cost of disposal/market adjustment | 16.30% | 17.90%
Commitments To Originate Real Estate Loans For Sale [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair value | $ 474 | $ 117
Commitments To Originate Real Estate Loans For Sale [Member] | Discounted Cash Flow [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Embedded servicing value | 1.00% | 1.00%
Mortgage Servicing Rights [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair value | $ 573 |
Mortgage Servicing Rights [Member] | Discounted Cash Flow [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Weighted average constant prepayment rate | 11.80% |
Weighted average discount rate | 2.24% |
Adequate compensation | $ 7 |

X
- Definition Adequate compensation per loan, used as an input to measure fair value. + References No definition available. + Details
Name: | cbu_FairValueInputsAdequateCompensation
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Embedded servicing value, used as an input to measure fair value. + References No definition available. + Details
Name: | cbu_FairValueInputsEmbeddedServicingValue
Namespace Prefix: | cbu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Adjustment to the appraisal used to measure fair value for estimated cost of disposal or market adjustment. + References No definition available. + Details
Name: | cbu_FairValueInputsEstimatedCostOfDisposalOrMarketAdjustment
Namespace Prefix: | cbu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
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_FairValueInputsAssetsQuantitativeInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Rate at which loans or a loan portfolio are expected to prepay principal balances, used as an input to measure fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsPrepaymentRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=cbu_OtherRealEstateOwnedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=us-gaap_MarketApproachValuationTechniqueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=cbu_ImpairedLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=cbu_CommitmentsToOriginateRealEstateLoansForSaleMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=cbu_DiscountedCashFlowMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=cbu_MortgageServicingRightsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |