XML 117 R101.htm IDEA: XBRL DOCUMENT v3.22.1

COMMITMENTS AND CONTINGENCIES - Off-Balance Sheet Risk (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fixed Rate | Commitments to make loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amounts of financial instruments with off-balance sheet risk	$ 20,772	$ 28,459
Fixed Rate | Unused lines of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amounts of financial instruments with off-balance sheet risk	4,745	1,300
Fixed Rate | Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amounts of financial instruments with off-balance sheet risk	0	0
Variable Rate | Commitments to make loans
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amounts of financial instruments with off-balance sheet risk	46,558	39,056
Variable Rate | Unused lines of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amounts of financial instruments with off-balance sheet risk	288,368	268,075
Variable Rate | Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Contractual amounts of financial instruments with off-balance sheet risk	$ 7,974	$ 16,094

X

- Definition

The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=123594938&loc=d3e13433-108611

+ Details

Name:	us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_FairValueOffBalanceSheetRisksDisclosureInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_DebtInstrumentAxis=chmg_FixedInterestRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommitmentsToExtendCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_UnusedLinesOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DebtInstrumentAxis=chmg_VariableInterestRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: