XML 54 R43.htm IDEA: XBRL DOCUMENT
v3.23.1

LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowances by Impairment (Details) - USD ($) $ in Thousands | Mar. 31, 2023 | Dec. 31, 2022 | Mar. 31, 2022 | Dec. 31, 2021
--- | --- | --- | --- | ---
Allowance for loan losses |  |  |  |  |  |
Individually evaluated for impairment | $ 1,076 |  | $ 1,147 |  |  |
Collectively evaluated for impairment | 18,999 |  | 18,512 |  |  |
Total ending allowance balance | 20,075 | [1] | 19,659 | [1] | $ 19,928 | $ 21,025
Loans: |  |  |  |  |  |
Loans individually analyzed | 6,837 |  | 7,482 |  |  |
Loans collectively analyzed | 1,866,864 |  | 1,821,966 |  |  |
Total loans, net of deferred loan fees and costs | 1,873,701 |  | 1,829,448 |  |  |
Collateral Pledged |  |  |  |  |  |
Allowance for loan losses |  |  |  |  |  |
Total ending allowance balance | 204 |  |  |  |  |
Loans: |  |  |  |  |  |
Loans individually analyzed | 5,955 |  |  |  |  |
Commercial and Agricultural |  |  |  |  |  |
Allowance for loan losses |  |  |  |  |  |
Individually evaluated for impairment | 1,040 |  | 1,078 |  |  |
Collectively evaluated for impairment | 3,013 |  | 2,295 |  |  |
Total ending allowance balance | 4,053 |  | 3,373 |  | 3,483 | 3,591
Loans: |  |  |  |  |  |
Loans individually analyzed | 1,779 |  | 2,112 |  |  |
Loans collectively analyzed | 242,728 |  | 250,181 |  |  |
Total loans, net of deferred loan fees and costs | 244,507 |  | 252,293 |  |  |
Commercial Mortgages |  |  |  |  |  |
Allowance for loan losses |  |  |  |  |  |
Individually evaluated for impairment | 36 |  | 38 |  |  |
Collectively evaluated for impairment | 10,947 |  | 11,538 |  |  |
Total ending allowance balance | 10,983 |  | 11,576 |  | 12,964 | 13,556
Loans: |  |  |  |  |  |
Loans individually analyzed | 4,089 |  | 4,383 |  |  |
Loans collectively analyzed | 1,032,208 |  | 992,530 |  |  |
Total loans, net of deferred loan fees and costs | 1,036,297 |  | 996,913 |  |  |
Residential Mortgages |  |  |  |  |  |
Allowance for loan losses |  |  |  |  |  |
Individually evaluated for impairment | 0 |  | 0 |  |  |
Collectively evaluated for impairment | 1,892 |  | 1,845 |  |  |
Total ending allowance balance | 1,892 |  | 1,845 |  | 1,606 | 1,803
Loans: |  |  |  |  |  |
Loans individually analyzed | 715 |  | 723 |  |  |
Loans collectively analyzed | 285,229 |  | 284,949 |  |  |
Total loans, net of deferred loan fees and costs | 285,944 |  | 285,672 |  |  |
Consumer Loans |  |  |  |  |  |
Allowance for loan losses |  |  |  |  |  |
Individually evaluated for impairment | 0 |  | 31 |  |  |
Collectively evaluated for impairment | 3,147 |  | 2,834 |  |  |
Total ending allowance balance | 3,147 |  | 2,865 |  | $ 1,875 | $ 2,075
Loans: |  |  |  |  |  |
Loans individually analyzed | 254 |  | 264 |  |  |
Loans collectively analyzed | 306,699 |  | 294,306 |  |  |
Total loans, net of deferred loan fees and costs | $ 306,953 |  | $ 294,570 |  |  |
[1] | Effective January 1, 2023, the allowance calculation is based upon Current Expected Credit loss methodology. Prior to January 1, 2023, the allowance calculation was based upon incurred loss methodology. Refer to Note 1 for further discussion.

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

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

X
- Definition Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The balance of financing receivables that were collectively evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (h) -URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableCollectivelyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI https://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 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 3B -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120267963-210447 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The balance of financing receivables that were individually evaluated for impairment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (h) -URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_CollateralAxis=us-gaap_CollateralPledgedMember
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_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: |