XML 57 R45.htm IDEA: XBRL DOCUMENT v3.8.0.1

LOANS, Credit Quality By Past Due Status (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017
Aged analysis of the company's loans [Abstract]
Total loans		$ 6,227,030	$ 6,256,757
Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		5,894	2,508
Nonaccrual		15,161	16,020
Total past due		47,512	51,563
Current		4,644,368	4,568,100
Total loans		4,691,880	4,619,663
Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		26,457	33,035
Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		531	204
Nonaccrual		8,078	8,720
Total past due		15,452	17,167
Acquired impaired	[1]	8,496	10,115
Current		1,511,202	1,609,812
Total loans		1,535,150	1,637,094
Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		6,843	8,243
Business Lending [Member]
Aged analysis of the company's loans [Abstract]
Total loans		2,426,086	2,424,223
Business Lending [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,450,006	1,376,599
Business Lending [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		976,080	1,047,624
Consumer Mortgage [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,765,864	1,754,609
Consumer Mortgage [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		446,018	465,689
Consumer Indirect [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		990,766	991,836
Consumer Indirect [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		17,432	20,142
Consumer Direct [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		168,517	174,479
Consumer Direct [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		4,515	5,450
Home Equity [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		316,727	322,140
Home Equity [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		91,105	98,189
Commercial Portfolio Segment [Member] | Business Lending [Member]
Aged analysis of the company's loans [Abstract]
Total loans		2,426,086	2,424,223
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		4,069	571
Nonaccrual		3,831	3,944
Total past due		12,962	6,798
Current		1,437,044	1,369,801
Total loans		1,450,006	1,376,599
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		5,062	2,283
Commercial Portfolio Segment [Member] | Business Lending [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		0	0
Nonaccrual		3,967	4,328
Total past due		8,086	8,989
Acquired impaired	[1]	8,496	10,115
Current		959,498	1,028,520
Total loans		976,080	1,047,624
Commercial Portfolio Segment [Member] | Business Lending [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		4,119	4,661
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Aged analysis of the company's loans [Abstract]
Total loans		2,211,882	2,220,298
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		1,437	1,500
Nonaccrual		10,086	10,722
Total past due		21,759	25,786
Current		1,744,105	1,728,823
Total loans		1,765,864	1,754,609
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		10,236	13,564
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		282	26
Nonaccrual		2,855	3,066
Total past due		5,128	5,695
Acquired impaired	[1]	0	0
Current		440,890	459,994
Total loans		446,018	465,689
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,991	2,603
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,008,198	1,011,978
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		182	295
Nonaccrual		5	0
Total past due		8,851	14,492
Current		981,915	977,344
Total loans		990,766	991,836
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		8,664	14,197
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		35	8
Nonaccrual		0	0
Total past due		141	253
Acquired impaired	[1]	0	0
Current		17,291	19,889
Total loans		17,432	20,142
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		106	245
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Aged analysis of the company's loans [Abstract]
Total loans		173,032	179,929
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		30	48
Nonaccrual		0	0
Total past due		1,121	1,923
Current		167,396	172,556
Total loans		168,517	174,479
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,091	1,875
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		0	0
Nonaccrual		0	0
Total past due		105	100
Acquired impaired	[1]	0	0
Current		4,410	5,350
Total loans		4,515	5,450
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		105	100
Consumer Portfolio Segment [Member] | Home Equity [Member]
Aged analysis of the company's loans [Abstract]
Total loans		407,832	420,329
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		176	94
Nonaccrual		1,239	1,354
Total past due		2,819	2,564
Current		313,908	319,576
Total loans		316,727	322,140
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,404	1,116
Consumer Portfolio Segment [Member] | Home Equity [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		214	170
Nonaccrual		1,256	1,326
Total past due		1,992	2,130
Acquired impaired	[1]	0	0
Current		89,113	96,059
Total loans		91,105	98,189
Consumer Portfolio Segment [Member] | Home Equity [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		$ 522	$ 634
[1] Acquired impaired loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cashflows, is being recognized on all acquired impaired loans.

X

- Definition

Loans acquired after January 1, 2009 that have evidence of deterioration in credit quality since origination and for which it is probable, at acquisition, that the company will be unable to collect all contractually required payments.

+ References

No definition available.

+ Details

Name:	cbu_FinancingReceivableRecordedInvestmentPurchasedImpaired
Namespace Prefix:	cbu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Recorded investment in financing receivables that are 90 days or more past due and still accruing.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524

+ Details

Name:	us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- References

No definition available.

+ Details

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

X

- Definition

Financing receivables that are current.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524

+ Details

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

X

- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524

+ Details

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

X

- Definition

Recorded Investment in financing receivables that are past due at the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7A
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953401-111524

+ Details

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

X

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

+ Details

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

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_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=cbu_AcquiredLoansMember
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: