XML 84 R68.htm IDEA: XBRL DOCUMENT
v3.24.0.1

LOANS AND ALLOWANCE FOR CREDIT LOSSES - Performance of Loan Modifications (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 USD ($)
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 2,379
Total Class of Financing Receivable (in percent) | 0.02%
Financial Asset, Not Past Due |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 2,098
Past Due 30 - 89 Days |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
90+ Days Past Due and Still Accruing |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Non-Accrual |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 281
Term Extension |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 2,379
Commercial Portfolio Segment | CRE - owner occupied |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 1,367
Total Class of Financing Receivable (in percent) | 0.18%
Commercial Portfolio Segment | CRE - owner occupied | Financial Asset, Not Past Due |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 1,367
Commercial Portfolio Segment | CRE - owner occupied | Past Due 30 - 89 Days |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Commercial Portfolio Segment | CRE - owner occupied | 90+ Days Past Due and Still Accruing |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Commercial Portfolio Segment | CRE - owner occupied | Non-Accrual |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Commercial Portfolio Segment | CRE - owner occupied | Term Extension |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 1,367
Commercial Portfolio Segment | CRE - non-owner occupied |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 700
Total Class of Financing Receivable (in percent) | 0.04%
Commercial Portfolio Segment | CRE - non-owner occupied | Financial Asset, Not Past Due |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 700
Commercial Portfolio Segment | CRE - non-owner occupied | Past Due 30 - 89 Days |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Commercial Portfolio Segment | CRE - non-owner occupied | 90+ Days Past Due and Still Accruing |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Commercial Portfolio Segment | CRE - non-owner occupied | Non-Accrual |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Commercial Portfolio Segment | CRE - non-owner occupied | Term Extension |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 700
Consumer Portfolio Segment | Consumer mortgage |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 281
Total Class of Financing Receivable (in percent) | 0.01%
Consumer Portfolio Segment | Consumer mortgage | Financial Asset, Not Past Due |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 0
Consumer Portfolio Segment | Consumer mortgage | Past Due 30 - 89 Days |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Consumer Portfolio Segment | Consumer mortgage | 90+ Days Past Due and Still Accruing |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Consumer Portfolio Segment | Consumer mortgage | Non-Accrual |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 281
Consumer Portfolio Segment | Consumer mortgage | Term Extension |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 281
Residential Portfolio Segment | Home equity |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 31
Total Class of Financing Receivable (in percent) | 0.01%
Residential Portfolio Segment | Home equity | Financial Asset, Not Past Due |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 31
Residential Portfolio Segment | Home equity | Past Due 30 - 89 Days |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Residential Portfolio Segment | Home equity | 90+ Days Past Due and Still Accruing |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Residential Portfolio Segment | Home equity | Non-Accrual |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | 0
Residential Portfolio Segment | Home equity | Term Extension |
LOANS AND ALLOWANCE FOR CREDIT LOSSES |
Loan modifications amount | $ 31

X
- Definition Amortized cost excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-42 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage, excluding accrued interest, of financing receivable modified during period for debtor experiencing financial difficulty to total financing receivables. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-42 + Details
Name: | us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-42 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 42 -Subparagraph (a)(2) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-42 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 12A -Publisher FASB -URI https://asc.fasb.org//1943274/2147481933/310-10-55-12A Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 33 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-33 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 34 -Publisher FASB -URI https://asc.fasb.org//1943274/2147481962/310-10-50-34 + Details
Name: | us-gaap_FinancingReceivableModificationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetNotPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=cbu_FinancingReceivables30To89DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=cbu_FinancingReceivables90PlusDaysPastDueAndStillAccruingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=cbu_FinancingReceivablesNonAccrualMember
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_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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