XML 83 R67.htm IDEA: XBRL DOCUMENT v3.22.1

LOANS AND ALLOWANCE FOR LOAN LOSSES - Credit Quality Indicator (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 1,522,382	$ 1,541,498
Loans	1,497,224	1,515,539
Not Rated
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	457,240	448,787
Pass
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	1,006,069	1,036,759
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	33,964	26,630
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	22,901	26,813
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,208	2,509
Commercial, and Agricultural
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	258,013	370,252
Commercial mortgages:
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	804,825	719,145
Commercial mortgages: | Construction
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	82,435	62,164
Commercial mortgages: | Commercial mortgages
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	722,390	656,981
Commercial mortgages: | Not Rated | Construction
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Commercial mortgages: | Not Rated | Commercial mortgages
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Commercial mortgages: | Pass | Construction
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	82,404	59,885
Commercial mortgages: | Pass | Commercial mortgages
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	672,741	616,090
Commercial mortgages: | Special Mention | Construction
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Commercial mortgages: | Special Mention | Commercial mortgages
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	31,072	23,631
Commercial mortgages: | Substandard | Construction
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	31	2,279
Commercial mortgages: | Substandard | Commercial mortgages
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	17,458	16,128
Commercial mortgages: | Doubtful | Construction
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Commercial mortgages: | Doubtful | Commercial mortgages
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	1,119	1,132
Residential Mortgages
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	259,967	240,013
Loans	259,967	240,013
Residential Mortgages | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	258,928	238,381
Residential Mortgages | Non-Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	1,039	1,632
Residential Mortgages | Not Rated
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	258,928	238,381
Residential Mortgages | Pass
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans		0
Residential Mortgages | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Residential Mortgages | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	1,039	1,632
Residential Mortgages | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Consumer Loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	199,577	212,088
Consumer Loans | Home equity lines and loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	70,854	78,761
Loans	70,854	78,761
Consumer Loans | Home equity lines and loans | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	70,064	77,602
Consumer Loans | Home equity lines and loans | Non-Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	790	1,159
Consumer Loans | Indirect Consumer Loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	118,855	120,853
Loans	118,855	120,853
Consumer Loans | Indirect Consumer Loans | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	118,393	120,334
Consumer Loans | Indirect Consumer Loans | Non-Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	462	519
Consumer Loans | Direct consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	9,868	12,474
Loans	9,868	12,474
Consumer Loans | Direct consumer loans | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	9,855	12,470
Consumer Loans | Direct consumer loans | Non-Performing
Financing Receivable, Recorded Investment [Line Items]
Loans	13	4
Consumer Loans | Not Rated | Home equity lines and loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	70,064	77,602
Consumer Loans | Not Rated | Indirect Consumer Loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	118,393	120,334
Consumer Loans | Not Rated | Direct consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	9,855	12,470
Consumer Loans | Pass | Home equity lines and loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Consumer Loans | Pass | Indirect Consumer Loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Consumer Loans | Pass | Direct consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Consumer Loans | Special Mention | Home equity lines and loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Consumer Loans | Special Mention | Indirect Consumer Loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Consumer Loans | Special Mention | Direct consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Consumer Loans | Substandard | Home equity lines and loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	790	1,159
Consumer Loans | Substandard | Indirect Consumer Loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	462	519
Consumer Loans | Substandard | Direct consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	13	4
Consumer Loans | Doubtful | Home equity lines and loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Consumer Loans | Doubtful | Indirect Consumer Loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Consumer Loans | Doubtful | Direct consumer loans
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Commercial and industrial | Commercial, and Agricultural
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	257,618	369,968
Commercial and industrial | Commercial, and Agricultural | Not Rated
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Commercial and industrial | Commercial, and Agricultural | Pass
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	250,529	360,500
Commercial and industrial | Commercial, and Agricultural | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	2,892	2,999
Commercial and industrial | Commercial, and Agricultural | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	3,108	5,092
Commercial and industrial | Commercial, and Agricultural | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	1,089	1,377
Agricultural | Commercial, and Agricultural
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	395	284
Agricultural | Commercial, and Agricultural | Not Rated
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Agricultural | Commercial, and Agricultural | Pass
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	395	284
Agricultural | Commercial, and Agricultural | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Agricultural | Commercial, and Agricultural | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	0	0
Agricultural | Commercial, and Agricultural | Doubtful
Financing Receivable, Recorded Investment [Line Items]
Total recorded investment in loans	$ 0	$ 0

X

- Definition

Financing Receivable, after Interest Receivable on Loans, before Allowance on Credit Loss

+ References

No definition available.

+ Details

Name:	chmg_FinancingReceivableAfterInterestReceivableOnLoansBeforeAllowanceOnCreditLoss
Namespace Prefix:	chmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=124259787&loc=d3e4428-111522

+ Details

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

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=chmg_NotRatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SpecialMentionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=chmg_CommercialAndAgriculturalPortfolioSegmentMember
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_ConstructionLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=chmg_CommercialMortgagesOtherLoansMember
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_FinancialInstrumentPerformanceStatusAxis=us-gaap_PerformingFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentPerformanceStatusAxis=us-gaap_NonperformingFinancingReceivableMember
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_HomeEquityLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=chmg_IndirectConsumerLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=chmg_DirectConsumerLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_EquitySecuritiesByIndustryAxis=us-gaap_CommercialAndIndustrialSectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_EquitySecuritiesByIndustryAxis=us-gaap_AgriculturalSectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: