XML 73 R46.htm IDEA: XBRL DOCUMENT
v3.20.1

LOANS AND ALLOWANCE FOR LOAN LOSSES - Credit Quality Indicator (Details) - USD ($) $ in Thousands | Mar. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Finance receivable by credit quality indicator [Abstract] |  |
Loans | $ 1,324,220 | $ 1,312,903
Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 422,232 | 428,037
Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 845,956 | 826,396
Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 17,733 | 18,534
Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 28,163 | 29,701
Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 10,136 | 10,235
Commercial and agricultural |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 236,650 | 230,922
Commercial Mortgages |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 661,661 | 650,570
Commercial Mortgages | Construction |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 41,073 | 44,082
Commercial Mortgages | Construction | Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Commercial Mortgages | Construction | Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 37,123 | 40,304
Commercial Mortgages | Construction | Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 398 | 168
Commercial Mortgages | Construction | Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 3,552 | 3,610
Commercial Mortgages | Construction | Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Commercial Mortgages | Commercial mortgages |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 620,588 | 606,488
Commercial Mortgages | Commercial mortgages | Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Commercial Mortgages | Commercial mortgages | Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 593,742 | 577,266
Commercial Mortgages | Commercial mortgages | Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 11,483 | 12,451
Commercial Mortgages | Commercial mortgages | Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 11,008 | 12,356
Commercial Mortgages | Commercial mortgages | Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 4,355 | 4,415
Residential mortgages |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 193,269 | 188,874
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 193,269 | 188,874
Residential mortgages | Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 191,004 | 186,719
Residential mortgages | Non-Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 2,265 | 2,155
Residential mortgages | Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 191,004 | 186,719
Residential mortgages | Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Residential mortgages | Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Residential mortgages | Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 2,265 | 2,155
Residential mortgages | Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Consumer Loans |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 232,640 | 242,537
Consumer Loans | Credit cards |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans |  | 0
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 0 | 0
Consumer Loans | Credit cards | Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 0 | 0
Consumer Loans | Credit cards | Non-Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 0 | 0
Consumer Loans | Credit cards | Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans |  | 0
Consumer Loans | Credit cards | Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans |  | 0
Consumer Loans | Credit cards | Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans |  | 0
Consumer Loans | Credit cards | Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans |  | 0
Consumer Loans | Credit cards | Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans |  | 0
Consumer Loans | Home equity lines and loans |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 88,421 | 92,065
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 88,421 | 92,065
Consumer Loans | Home equity lines and loans | Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 87,783 | 91,424
Consumer Loans | Home equity lines and loans | Non-Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 638 | 641
Consumer Loans | Home equity lines and loans | Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 87,783 | 91,424
Consumer Loans | Home equity lines and loans | Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Consumer Loans | Home equity lines and loans | Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Consumer Loans | Home equity lines and loans | Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 638 | 641
Consumer Loans | Home equity lines and loans | Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Consumer Loans | Indirect consumer loans |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 129,809 | 135,366
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 129,809 | 135,366
Consumer Loans | Indirect consumer loans | Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 129,042 | 134,795
Consumer Loans | Indirect consumer loans | Non-Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 767 | 571
Consumer Loans | Indirect consumer loans | Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 129,042 | 134,795
Consumer Loans | Indirect consumer loans | Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Consumer Loans | Indirect consumer loans | Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Consumer Loans | Indirect consumer loans | Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 767 | 571
Consumer Loans | Indirect consumer loans | Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Consumer Loans | Direct consumer loans |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 14,410 | 15,106
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 14,410 | 15,106
Consumer Loans | Direct consumer loans | Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 14,403 | 15,099
Consumer Loans | Direct consumer loans | Non-Performing |  |
Residential and consumer finance receivable [Abstract] |  |
Residential and consumer loans receivable | 7 | 7
Consumer Loans | Direct consumer loans | Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 14,403 | 15,099
Consumer Loans | Direct consumer loans | Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Consumer Loans | Direct consumer loans | Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Consumer Loans | Direct consumer loans | Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 7 | 7
Consumer Loans | Direct consumer loans | Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Commercial and industrial | Commercial and agricultural |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 236,360 | 230,648
Commercial and industrial | Commercial and agricultural | Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Commercial and industrial | Commercial and agricultural | Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 214,801 | 208,552
Commercial and industrial | Commercial and agricultural | Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 5,852 | 5,915
Commercial and industrial | Commercial and agricultural | Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 9,926 | 10,361
Commercial and industrial | Commercial and agricultural | Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 5,781 | 5,820
Agricultural | Commercial and agricultural |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 290 | 274
Agricultural | Commercial and agricultural | Not Rated |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Agricultural | Commercial and agricultural | Pass |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 290 | 274
Agricultural | Commercial and agricultural | Special Mention |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Agricultural | Commercial and agricultural | Substandard |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | 0 | 0
Agricultural | Commercial and agricultural | Doubtful |  |
Finance receivable by credit quality indicator [Abstract] |  |
Loans | $ 0 | $ 0

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

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

X
- Definition The amount of finance receivable related to residential and consumer loans receivable.. + References No definition available. + Details
Name: | chmg_ResidentialAndConsumerLoansReceivable
Namespace Prefix: | chmg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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=119407570&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=6877327&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=118952595&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_CreditCardReceivablesMember
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: |