Average Loan Balance

No definition available.

Name:	chco_AverageLoanBalance
Namespace Prefix:	chco_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of Loans

+ References

No definition available.

+ Details

Name:	chco_NumberofLoans
Namespace Prefix:	chco_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

% of Loans in Flood Zone

+ References

No definition available.

+ Details

Name:	chco_OfLoansinFloodZone
Namespace Prefix:	chco_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4428-111522

+ Details

Name:	us-gaap_LoansAndLeasesReceivableGrossCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=25495931&loc=d3e18794-111554

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=chco_CommercialIndustrialLoansAndCommercialRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=us-gaap_FloodMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Allowance For Loan Losses (Narrative) (Details)	6 Months Ended
Allowance For Loan Losses (Narrative) (Details)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Financing Receivable, Impaired [Line Items]
Gross loans	$ 2,903,398,000		$ 2,862,534,000
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	200,000	$ 400,000
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Gross loans	1,417,137,000		1,383,133,000
Commercial Industrial Loans And Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Gross loans	1,306,855,000		1,292,921,000
Consumer Loan [Member]
Financing Receivable, Impaired [Line Items]
Gross loans	33,799,000		$ 36,083,000
Flood [Member]
Financing Receivable, Impaired [Line Items]
Gross loans	$ 40,000,000
% of Loans in Flood Zone	90.00%
Number of Loans	900
Average Loan Balance	$ 43,000