XML 62 R50.htm IDEA: XBRL DOCUMENT
v3.21.2

LOANS - Troubled Debt Restructurings (TDRs) (Details) $ in Thousands | 6 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2021 USD ($) loan borrower | Jun. 30, 2020 USD ($) loan | Dec. 31, 2020 USD ($) loan borrower
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 228 |  | 247
TDRs, amount | $ 6,682 |  | $ 6,984
Loans modified in TDR during the year, number | loan | 16 | 7 |
Loans modified in TDR during the year, amount | $ 482 | $ 249 |
Number of borrowers representing $75.6 million in outstanding loan balances | borrower | 12 |  |
Outstanding loan balances of 47 number of borrowers | $ 2,400 |  |
Percentage of total loan outstanding | 0.03% |  | 0.90%
Number of business borrowers representing $75.1 million in outstanding loan balances | borrower | 8 |  |
Outstanding loan balances of 42 number of business borrowers | $ 2,000 |  |
Number of consumer borrowers representing $0.5 million in outstanding loan balances | borrower | 4 |  |
Outstanding loan balances of 5 number of consumer borrowers | $ 400 |  |
Number of borrowers representing $66.5 million in outstanding loan balances | borrower |  |  | 74
Outstanding loan balances of 74 number of borrowers |  |  | $ 66,500
Number of borrowers representing $65.7 million in outstanding loan balances | borrower |  |  | 63
Outstanding loan balances of 63 number of borrowers |  |  | $ 65,700
Number of borrowers representing $0.8 million in outstanding loan balances | borrower |  |  | 11
Outstanding loan balances of 11 number of borrowers |  |  | $ 800
Minimum [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
Threshold balance of loan individually evaluated for impairment | 500 |  |
Maximum [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
Threshold balance of TDR loans collectively included in general loan loss allocation and qualitative review | $ 500 |  |
Nonaccrual [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 74 |  | 73
TDRs, amount | $ 3,250 |  | $ 3,227
Accruing [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 154 |  | 174
TDRs, amount | $ 3,432 |  | $ 3,757
Commercial Portfolio Segment [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
Loans modified in TDR during the year, number | loan | 26 | 25 |
Loans modified in TDR during the year, amount | $ 657 | $ 928 |
Commercial Portfolio Segment [Member] | Business Lending [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 10 |  | 10
TDRs, amount | $ 625 |  | $ 720
Loans modified in TDR during the year, number | loan | 0 | 0 |
Loans modified in TDR during the year, amount | $ 0 | $ 0 |
Commercial Portfolio Segment [Member] | Business Lending [Member] | Nonaccrual [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 6 |  | 6
TDRs, amount | $ 445 |  | $ 529
Commercial Portfolio Segment [Member] | Business Lending [Member] | Accruing [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 4 |  | 4
TDRs, amount | $ 180 |  | $ 191
Commercial Portfolio Segment [Member] | Consumer Mortgage [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
Loans modified in TDR during the year, number | loan | 10 | 9 |
Loans modified in TDR during the year, amount | $ 474 | $ 738 |
Commercial Portfolio Segment [Member] | Consumer Indirect [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
Loans modified in TDR during the year, number | loan | 15 | 14 |
Loans modified in TDR during the year, amount | $ 177 | $ 151 |
Commercial Portfolio Segment [Member] | Consumer Direct [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
Loans modified in TDR during the year, number | loan | 1 | 1 |
Loans modified in TDR during the year, amount | $ 6 | $ 11 |
Commercial Portfolio Segment [Member] | Home Equity [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
Loans modified in TDR during the year, number | loan | 0 | 1 |
Loans modified in TDR during the year, amount | $ 0 | $ 28 |
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 100 |  | 104
TDRs, amount | $ 4,627 |  | $ 4,679
Loans modified in TDR during the year, number | loan | 7 | 3 |
Loans modified in TDR during the year, amount | $ 366 | $ 174 |
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Nonaccrual [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 58 |  | 56
TDRs, amount | $ 2,553 |  | $ 2,413
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Accruing [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 42 |  | 48
TDRs, amount | $ 2,074 |  | $ 2,266
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 79 |  | 86
TDRs, amount | $ 916 |  | $ 951
Loans modified in TDR during the year, number | loan | 9 | 3 |
Loans modified in TDR during the year, amount | $ 116 | $ 47 |
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Nonaccrual [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 0 |  | 0
TDRs, amount | $ 0 |  | $ 0
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Accruing [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 79 |  | 86
TDRs, amount | $ 916 |  | $ 951
Consumer Portfolio Segment [Member] | Consumer Direct [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 17 |  | 23
TDRs, amount | $ 14 |  | $ 85
Loans modified in TDR during the year, number | loan | 0 | 0 |
Loans modified in TDR during the year, amount | $ 0 | $ 0 |
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Nonaccrual [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 0 |  | 0
TDRs, amount | $ 0 |  | $ 0
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Accruing [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 17 |  | 23
TDRs, amount | $ 14 |  | $ 85
Consumer Portfolio Segment [Member] | Home Equity [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 22 |  | 24
TDRs, amount | $ 500 |  | $ 549
Loans modified in TDR during the year, number | loan | 0 | 1 |
Loans modified in TDR during the year, amount | $ 0 | $ 28 |
Consumer Portfolio Segment [Member] | Home Equity [Member] | Nonaccrual [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 10 |  | 11
TDRs, amount | $ 252 |  | $ 285
Consumer Portfolio Segment [Member] | Home Equity [Member] | Accruing [Member] |  |  |
Troubled Debt Restructurings (TDRs) |  |  |
TDRs, number | loan | 12 |  | 13
TDRs, amount | $ 248 |  | $ 264

X
- Definition The threshold balance of financing receivable that is individually evaluated for impairment. + References No definition available. + Details
Name: | cbu_FinancingReceivableIndividuallyEvaluatedForImpairmentThresholdBalance
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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 It represents number of borrowers representing $0.8 million in outstanding loan balances + References No definition available. + Details
Name: | cbu_NumberOfBorrowersRepresenting0.8MillionInOutstandingLoanBalances
Namespace Prefix: | cbu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition It represents number of borrowers representing $65.7 million in outstanding loan balances + References No definition available. + Details
Name: | cbu_NumberOfBorrowersRepresenting65.7MillionInOutstandingLoanBalances
Namespace Prefix: | cbu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition It represents number of borrowers representing $66.5 million in outstanding loan balances + References No definition available. + Details
Name: | cbu_NumberOfBorrowersRepresenting66.5MillionInOutstandingLoanBalances
Namespace Prefix: | cbu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition It represents number of borrowers representing $75.6 million in outstanding loan balances + References No definition available. + Details
Name: | cbu_NumberOfBorrowersRepresenting75.6MillionInOutstandingLoanBalances
Namespace Prefix: | cbu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition It represents number of business borrowers representing $75.1 million in outstanding loan balances + References No definition available. + Details
Name: | cbu_NumberOfBusinessBorrowersRepresenting75.1MillionInOutstandingLoanBalances
Namespace Prefix: | cbu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition It represents number of consumer borrowers representing $0.5 million in outstanding loan balances. + References No definition available. + Details
Name: | cbu_NumberOfConsumerBorrowersRepresenting0.5MillionInOutstandingLoanBalances
Namespace Prefix: | cbu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition It represents outstanding loan balances of 11 number of borrowers + References No definition available. + Details
Name: | cbu_OutstandingLoanBalancesOf11NumberOfBorrowers
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition It represents outstanding loan balances of 42 number of borrowers + References No definition available. + Details
Name: | cbu_OutstandingLoanBalancesOf42NumberOfBorrowers
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition It represents outstanding loan balances of 47 number of borrowers. + References No definition available. + Details
Name: | cbu_OutstandingLoanBalancesOf47NumberOfBorrowers
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition It represents outstanding loan balances of 5 number of borrowers. + References No definition available. + Details
Name: | cbu_OutstandingLoanBalancesOf5NumberOfConsumerBorrowers
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition It represents outstanding loan balances of 63 number of borrowers + References No definition available. + Details
Name: | cbu_OutstandingLoanBalancesOf63NumberOfBorrowers
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition It represents outstanding loan balances of 74 number of borrowers + References No definition available. + Details
Name: | cbu_OutstandingLoanBalancesOf74NumberOfBorrowers
Namespace Prefix: | cbu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition It represents percentage of loans outstanding + References No definition available. + Details
Name: | cbu_PercentageOfTotalLoansOutstanding
Namespace Prefix: | cbu_
Data Type: | num:percentItemType
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/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after troubled debt restructuring, of modified financing receivable. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of financing receivable modified as troubled debt restructuring. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_FinancingReceivableTroubledDebtRestructuringAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
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_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialMortgageMember
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: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
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: |