XML 66 R54.htm IDEA: XBRL DOCUMENT
v3.7.0.1

COMMITMENTS, CONTINGENT LIABILITIES AND RESTRICTIONS (Details) - USD ($) $ in Thousands | Jun. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Contract amount of commitments and contingencies | $ 948,550 | $ 796,098
Minimum [Member] |  |
Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Range of reasonably possible losses for such matters in the aggregate, beyond the existing recorded liability | 0 |
Maximum [Member] |  |
Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Range of reasonably possible losses for such matters in the aggregate, beyond the existing recorded liability | 1,000 |
Commitments to Extend Credit [Member] |  |
Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Contract amount of commitments and contingencies | 924,039 | 773,442
Standby Letters of Credit [Member] |  |
Off-balance Sheet Risks, Disclosure Information [Line Items] |  |
Contract amount of commitments and contingencies | $ 24,511 | $ 22,656

X
- Definition The face amount of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition. + References No definition available. + Details
Name: | cbu_FaceValueDisclosureOffBalanceSheetRisksFaceAmountLiability
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_FairValueOffBalanceSheetRisksDisclosureInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reflects the estimated amount of loss from the specified contingency as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 9 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349 + Details
Name: | us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_FinancialInstrumentAxis=us-gaap_CommitmentsToExtendCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |