XML 124 R109.htm IDEA: XBRL DOCUMENT
v3.3.1.900

FAIR VALUE, Significant Unobservable Inputs (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014
Impaired Loans [Member] | Fair Value of Collateral [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair value | $ 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 | 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 | 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 | 17.90% |
Other Real Estate Owned [Member] | Fair Value of Collateral [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair value | $ 2,088 | $ 1,855
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 | 5.30% | 10.00%
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 | 74.00% | 77.50%
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 | 27.70% | 30.60%
Commitments To Originate Real Estate Loans For Sale [Member] | Discounted Cash Flow [Member] |  |
Fair Value Inputs, Assets, Quantitative Information [Line Items] |  |
Fair value | $ 117 | $ 185
Embedded servicing value | 1.00% | 1.00%

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=36462937&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
- Details
Name: | us-gaap_FairValueByAssetClassAxis=cbu_ImpairedLoansMember
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_OtherRealEstateOwnedMember
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: |