XML 76 R65.htm IDEA: XBRL DOCUMENT
v3.23.1

REVENUE FROM CONTRACTS WITH CUSTOMERS (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Disaggregation of Revenue [Line Items] |  |
Changes in fair value of equity investments | $ 72 | $ (113)
Income from bank owned life insurance | 10 | 11
Other non-interest income | 5,423 | 5,663
Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Other non-interest income | 192 | 213
Overdraft fees |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 714 | 673
Other |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 227 | 191
Interchange revenue from debit card transactions |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 1,133 | 1,130
WMG fee income |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 2,580 | 2,757
CFS fee and commission income |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 241 | 253
Net gains (losses) on sales of OREO |  |
Disaggregation of Revenue [Line Items] |  |
Net gains (losses) on sales of OREO | 0 |
Net gains on sales of loans |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 5 | 74
Loan servicing fees |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 36 | 39
Income from bank-owned life insurance |  |
Disaggregation of Revenue [Line Items] |  |
Income from bank owned life insurance | 10 | 11
Other |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 405 | 648
Core Banking | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Changes in fair value of equity investments | 78 | (114)
Other non-interest income | 2,651 | 2,693
Core Banking | Overdraft fees | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 714 | 673
Core Banking | Other | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 227 | 191
Core Banking | Interchange revenue from debit card transactions | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 1,133 | 1,130
Core Banking | WMG fee income | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
Core Banking | CFS fee and commission income | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
Core Banking | Net gains (losses) on sales of OREO | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Net gains (losses) on sales of OREO | 0 |
Core Banking | Net gains on sales of loans | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 5 | 74
Core Banking | Loan servicing fees | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 36 | 39
Core Banking | Income from bank-owned life insurance | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Income from bank owned life insurance | 10 | 11
Core Banking | Other | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 448 | 689
WMG | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Changes in fair value of equity investments | 0 | 0
Other non-interest income | 2,580 | 2,757
WMG | Overdraft fees | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
WMG | Other | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
WMG | Interchange revenue from debit card transactions | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
WMG | WMG fee income | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 2,580 | 2,757
WMG | CFS fee and commission income | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
WMG | Net gains (losses) on sales of OREO | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Net gains (losses) on sales of OREO | 0 |
WMG | Net gains on sales of loans | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 0 | 0
WMG | Loan servicing fees | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 0 | 0
WMG | Income from bank-owned life insurance | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Income from bank owned life insurance | 0 | 0
WMG | Other | Operating Segments |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 0 | 0
Holding Company, CFS, and CRM | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Changes in fair value of equity investments | (6) | 1
Other non-interest income | 192 | 213
Holding Company, CFS, and CRM | Overdraft fees | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
Holding Company, CFS, and CRM | Other | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
Holding Company, CFS, and CRM | Interchange revenue from debit card transactions | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
Holding Company, CFS, and CRM | WMG fee income | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 0 | 0
Holding Company, CFS, and CRM | CFS fee and commission income | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Revenues from contracts with customer | 241 | 253
Holding Company, CFS, and CRM | Net gains (losses) on sales of OREO | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Net gains (losses) on sales of OREO | 0 |
Holding Company, CFS, and CRM | Net gains on sales of loans | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 0 | 0
Holding Company, CFS, and CRM | Loan servicing fees | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | 0 | 0
Holding Company, CFS, and CRM | Income from bank-owned life insurance | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Income from bank owned life insurance | 0 | 0
Holding Company, CFS, and CRM | Other | Intersegment Eliminations |  |
Disaggregation of Revenue [Line Items] |  |
Revenue not from contact with customer | $ (43) | $ (41)

X
- Definition Earnings on or other increases in the value of the cash surrender value of bank owned life insurance policies. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.13) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 + Details
Name: | us-gaap_BankOwnedLifeInsuranceIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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_DisaggregationOfRevenueLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=126980263&loc=SL75117546-209714 + Details
Name: | us-gaap_EquitySecuritiesFvNiGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The net gain (loss) resulting from sales and other disposals of other real estate owned, increases (decreases) in the valuation allowance for foreclosed real estate, and write-downs of other real estate owned after acquisition or physical possession. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.14(d)) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 + Details
Name: | us-gaap_GainsLossesOnSalesOfOtherRealEstate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.13) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 + Details
Name: | us-gaap_NoninterestIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 40 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9031-108599 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 41 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9038-108599 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130543-203045 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 42 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e9054-108599 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=126920106&loc=SL49130545-203045 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 924 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 11.L) -URI https://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856 + Details
Name: | us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue that is not accounted for under Topic 606. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(1)) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 + Details
Name: | us-gaap_RevenueNotFromContractWithCustomer
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_IntersegmentEliminationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_OverdraftFeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_ServiceChargeonDepositsOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_InterchangeRevenueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_WMGFeeIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_InvestmentBrokerageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_SaleofOREOMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_SaleofLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_LoanServicingFeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_IncomeFromBankOwnedLifeInsuranceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=chmg_ProductsAndServicesOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=chmg_CoreBankingSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=chmg_WealthManagementGroupServicesSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=chmg_HoldingCompanyCFSAndCRMMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |