XML 52 R41.htm IDEA: XBRL DOCUMENT
v3.22.2

LOANS AND ALLOWANCE FOR LOAN LOSSES - Allowances by Impairment (Details) - USD ($) $ in Thousands | Jun. 30, 2022 | Mar. 31, 2022 | Dec. 31, 2021 | Jun. 30, 2021 | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | --- | --- | --- | --- | ---
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | $ 17,485 | $ 19,928 | $ 21,025 | $ 20,676 | $ 20,909 | $ 20,924
Loans: |  |  |  |  |  |
Total recorded investment in loans | 1,621,993 |  | 1,522,382 |  |  |
Individually evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 1,326 |  | 3,030 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | 7,349 |  | 11,647 |  |  |
Collectively evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 16,159 |  | 17,995 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | 1,614,644 |  | 1,510,735 |  |  |
Commercial and Agricultural |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 3,564 | 3,485 | 3,591 | 3,628 | 4,337 | 4,493
Loans: |  |  |  |  |  |
Total recorded investment in loans | 259,308 |  | 258,013 |  |  |
Commercial and Agricultural | Individually evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 1,239 |  | 1,394 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | 1,925 |  | 2,427 |  |  |
Commercial and Agricultural | Collectively evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 2,325 |  | 2,197 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | 257,383 |  | 255,586 |  |  |
Commercial Mortgages |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 10,314 | 12,963 | 13,556 | 12,963 | 11,787 | 11,496
Loans: |  |  |  |  |  |
Total recorded investment in loans | 868,635 |  | 804,825 |  |  |
Commercial Mortgages | Individually evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 44 |  | 1,571 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | 4,210 |  | 7,967 |  |  |
Commercial Mortgages | Collectively evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 10,270 |  | 11,985 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | 864,425 |  | 796,858 |  |  |
Residential Mortgages |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 1,714 | 1,606 | 1,803 | 1,791 | 2,115 | 2,079
Loans: |  |  |  |  |  |
Total recorded investment in loans | 277,567 |  | 259,967 |  |  |
Residential Mortgages | Individually evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 0 |  | 0 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | 924 |  | 938 |  |  |
Residential Mortgages | Collectively evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 1,714 |  | 1,803 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | 276,643 |  | 259,029 |  |  |
Consumer Loans |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 1,893 | $ 1,874 | 2,075 | $ 2,294 | $ 2,670 | $ 2,856
Loans: |  |  |  |  |  |
Total recorded investment in loans | 216,483 |  | 199,577 |  |  |
Consumer Loans | Individually evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 43 |  | 65 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | 290 |  | 315 |  |  |
Consumer Loans | Collectively evaluated for impairment |  |  |  |  |  |
Allowance for loan losses: |  |  |  |  |  |
Total ending allowance balance | 1,850 |  | 2,010 |  |  |
Loans: |  |  |  |  |  |
Total recorded investment in loans | $ 216,193 |  | $ 199,262 |  |  |

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
- 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 of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement. + 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 (c)(1) -URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953423-111524 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(7)(2)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(4)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -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 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919249-210447 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (3) Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (c) Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (1) + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | chmg_ImpairmentEvaluationAxis=chmg_IndividuallyEvaluatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | chmg_ImpairmentEvaluationAxis=chmg_CollectivelyEvaluatedMember
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: |