XML 56 R44.htm IDEA: XBRL DOCUMENT v3.24.2.u1

LOANS AND ALLOWANCE FOR CREDIT LOSSES - Credit Quality By Past Due Status (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Aged analysis of the company's loans
Total Loans	$ 10,023,857	$ 9,704,598
Legacy Loan
Aged analysis of the company's loans
Total Loans	10,023,857	9,704,598
Nonaccrual	47,407	48,687
Legacy Loan | Past Due 30 - 89 Days
Aged analysis of the company's loans
Total Loans	45,074	48,442
Legacy Loan | 90+ Days Past Due and Still Accruing
Aged analysis of the company's loans
Total Loans	3,106	5,886
Legacy Loan | Financial Asset, Past Due
Aged analysis of the company's loans
Total Loans	95,587	103,015
Legacy Loan | Financial Asset, Not Past Due
Aged analysis of the company's loans
Total Loans	9,928,270	9,601,583
CRE - multifamily
Aged analysis of the company's loans
Total Loans	663,681	619,794
CRE - owner occupied
Aged analysis of the company's loans
Total Loans	816,630	752,774
CRE - non-owner occupied
Aged analysis of the company's loans
Total Loans	1,720,539	1,711,198
Commercial & industrial and other business loans
Aged analysis of the company's loans
Total Loans	1,093,323	1,000,630
Business lending
Aged analysis of the company's loans
Total Loans	4,294,173	4,084,396
Consumer mortgage
Aged analysis of the company's loans
Total Loans	3,368,166	3,285,018
Consumer indirect
Aged analysis of the company's loans
Total Loans	1,723,002	1,703,440
Consumer direct
Aged analysis of the company's loans
Total Loans	186,503	185,229
Home equity
Aged analysis of the company's loans
Total Loans	452,013	446,515
Commercial Portfolio Segment | CRE - multifamily
Aged analysis of the company's loans
Total Loans	663,681	619,794
Commercial Portfolio Segment | CRE - multifamily | Legacy Loan
Aged analysis of the company's loans
Total Loans	663,681	619,794
Nonaccrual	0	0
Commercial Portfolio Segment | CRE - multifamily | Legacy Loan | Past Due 30 - 89 Days
Aged analysis of the company's loans
Total Loans	141	0
Commercial Portfolio Segment | CRE - multifamily | Legacy Loan | 90+ Days Past Due and Still Accruing
Aged analysis of the company's loans
Total Loans	0	0
Commercial Portfolio Segment | CRE - multifamily | Legacy Loan | Financial Asset, Past Due
Aged analysis of the company's loans
Total Loans	141	0
Commercial Portfolio Segment | CRE - multifamily | Legacy Loan | Financial Asset, Not Past Due
Aged analysis of the company's loans
Total Loans	663,540	619,794
Commercial Portfolio Segment | CRE - owner occupied
Aged analysis of the company's loans
Total Loans	816,630	752,774
Commercial Portfolio Segment | CRE - non-owner occupied
Aged analysis of the company's loans
Total Loans	1,720,539	1,711,198
Commercial Portfolio Segment | Commercial & industrial and other business loans
Aged analysis of the company's loans
Total Loans	1,093,323	1,000,630
Residential Portfolio Segment | CRE - owner occupied | Legacy Loan
Aged analysis of the company's loans
Total Loans	816,630	752,774
Nonaccrual	3,089	1,953
Residential Portfolio Segment | CRE - owner occupied | Legacy Loan | Past Due 30 - 89 Days
Aged analysis of the company's loans
Total Loans	477	1,477
Residential Portfolio Segment | CRE - owner occupied | Legacy Loan | 90+ Days Past Due and Still Accruing
Aged analysis of the company's loans
Total Loans	0	0
Residential Portfolio Segment | CRE - owner occupied | Legacy Loan | Financial Asset, Past Due
Aged analysis of the company's loans
Total Loans	3,566	3,430
Residential Portfolio Segment | CRE - owner occupied | Legacy Loan | Financial Asset, Not Past Due
Aged analysis of the company's loans
Total Loans	813,064	749,344
Residential Portfolio Segment | Consumer mortgage
Aged analysis of the company's loans
Total Loans	3,368,166	3,285,018
Residential Portfolio Segment | Consumer mortgage | Legacy Loan
Aged analysis of the company's loans
Total Loans	3,368,166	3,285,018
Nonaccrual	27,897	26,043
Residential Portfolio Segment | Consumer mortgage | Legacy Loan | Past Due 30 - 89 Days
Aged analysis of the company's loans
Total Loans	20,004	18,434
Residential Portfolio Segment | Consumer mortgage | Legacy Loan | 90+ Days Past Due and Still Accruing
Aged analysis of the company's loans
Total Loans	2,129	4,559
Residential Portfolio Segment | Consumer mortgage | Legacy Loan | Financial Asset, Past Due
Aged analysis of the company's loans
Total Loans	50,030	49,036
Residential Portfolio Segment | Consumer mortgage | Legacy Loan | Financial Asset, Not Past Due
Aged analysis of the company's loans
Total Loans	3,318,136	3,235,982
Residential Portfolio Segment | Home equity | Legacy Loan
Aged analysis of the company's loans
Total Loans	452,013	446,515
Nonaccrual	2,487	2,368
Residential Portfolio Segment | Home equity | Legacy Loan | Past Due 30 - 89 Days
Aged analysis of the company's loans
Total Loans	2,685	3,546
Residential Portfolio Segment | Home equity | Legacy Loan | 90+ Days Past Due and Still Accruing
Aged analysis of the company's loans
Total Loans	455	416
Residential Portfolio Segment | Home equity | Legacy Loan | Financial Asset, Past Due
Aged analysis of the company's loans
Total Loans	5,627	6,330
Residential Portfolio Segment | Home equity | Legacy Loan | Financial Asset, Not Past Due
Aged analysis of the company's loans
Total Loans	446,386	440,185
Consumer Portfolio Segment | CRE - non-owner occupied | Legacy Loan
Aged analysis of the company's loans
Total Loans	1,720,539	1,711,198
Nonaccrual	13,364	17,964
Consumer Portfolio Segment | CRE - non-owner occupied | Legacy Loan | Past Due 30 - 89 Days
Aged analysis of the company's loans
Total Loans	93	2,311
Consumer Portfolio Segment | CRE - non-owner occupied | Legacy Loan | 90+ Days Past Due and Still Accruing
Aged analysis of the company's loans
Total Loans	0	0
Consumer Portfolio Segment | CRE - non-owner occupied | Legacy Loan | Financial Asset, Past Due
Aged analysis of the company's loans
Total Loans	13,457	20,275
Consumer Portfolio Segment | CRE - non-owner occupied | Legacy Loan | Financial Asset, Not Past Due
Aged analysis of the company's loans
Total Loans	1,707,082	1,690,923
Consumer Portfolio Segment | Commercial & industrial and other business loans | Legacy Loan
Aged analysis of the company's loans
Total Loans	1,093,323	1,000,630
Nonaccrual	550	336
Consumer Portfolio Segment | Commercial & industrial and other business loans | Legacy Loan | Past Due 30 - 89 Days
Aged analysis of the company's loans
Total Loans	329	880
Consumer Portfolio Segment | Commercial & industrial and other business loans | Legacy Loan | 90+ Days Past Due and Still Accruing
Aged analysis of the company's loans
Total Loans	0	0
Consumer Portfolio Segment | Commercial & industrial and other business loans | Legacy Loan | Financial Asset, Past Due
Aged analysis of the company's loans
Total Loans	879	1,216
Consumer Portfolio Segment | Commercial & industrial and other business loans | Legacy Loan | Financial Asset, Not Past Due
Aged analysis of the company's loans
Total Loans	1,092,444	999,414
Consumer Portfolio Segment | Consumer indirect
Aged analysis of the company's loans
Total Loans	1,723,002	1,703,440
Consumer Portfolio Segment | Consumer indirect | Legacy Loan
Aged analysis of the company's loans
Total Loans	1,723,002	1,703,440
Nonaccrual	0	0
Consumer Portfolio Segment | Consumer indirect | Legacy Loan | Past Due 30 - 89 Days
Aged analysis of the company's loans
Total Loans	19,664	20,215
Consumer Portfolio Segment | Consumer indirect | Legacy Loan | 90+ Days Past Due and Still Accruing
Aged analysis of the company's loans
Total Loans	436	776
Consumer Portfolio Segment | Consumer indirect | Legacy Loan | Financial Asset, Past Due
Aged analysis of the company's loans
Total Loans	20,100	20,991
Consumer Portfolio Segment | Consumer indirect | Legacy Loan | Financial Asset, Not Past Due
Aged analysis of the company's loans
Total Loans	1,702,902	1,682,449
Consumer Portfolio Segment | Consumer direct
Aged analysis of the company's loans
Total Loans	186,503	185,229
Consumer Portfolio Segment | Consumer direct | Legacy Loan
Aged analysis of the company's loans
Total Loans	186,503	185,229
Nonaccrual	20	23
Consumer Portfolio Segment | Consumer direct | Legacy Loan | Past Due 30 - 89 Days
Aged analysis of the company's loans
Total Loans	1,681	1,579
Consumer Portfolio Segment | Consumer direct | Legacy Loan | 90+ Days Past Due and Still Accruing
Aged analysis of the company's loans
Total Loans	86	135
Consumer Portfolio Segment | Consumer direct | Legacy Loan | Financial Asset, Past Due
Aged analysis of the company's loans
Total Loans	1,787	1,737
Consumer Portfolio Segment | Consumer direct | Legacy Loan | Financial Asset, Not Past Due
Aged analysis of the company's loans
Total Loans	184,716	183,492
Consumer Portfolio Segment | Home equity
Aged analysis of the company's loans
Total Loans	$ 452,013	$ 446,515

X

- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-3B

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-5

+ Details

Name:	us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amortized cost of financing receivable on nonaccrual status. Excludes net investment in lease.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph a
-Subparagraph (3)
-Publisher SEC

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph a
-Subparagraph (2)
-Publisher SEC

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 16
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479319/326-20-50-16

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- References

No definition available.

+ Details

Name:	us-gaap_PastDueFinancialInstrumentAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cbu_LegacyLoanMember
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=us-gaap_FinancialAssetPastDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cbu_CommercialRealEstateMultifamilyMember
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_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=cbu_CommercialIndustrialAndOtherBusinessLoansMember
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_CommercialPortfolioSegmentMember
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: