XML 43 R31.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Background and Basis of Presentation (Details) | 9 Months Ended
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Sep. 30, 2017 store
Entity Location [Line Items] |
Number of Reportable Segments | 1
City National |
Entity Location [Line Items] |
Number of Stores | 86
WEST VIRGINIA | City National |
Entity Location [Line Items] |
Number of Stores | 57
VIRGINIA | City National |
Entity Location [Line Items] |
Number of Stores | 14
KENTUCKY | City National |
Entity Location [Line Items] |
Number of Stores | 12
OHIO | City National |
Entity Location [Line Items] |
Number of Stores | 3

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- 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: | dei_EntityLocationLineItems
Namespace Prefix: | dei_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

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- Definition Represents the number of stores. + References No definition available. + Details
Name: | us-gaap_NumberOfStores
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

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- Details
Name: | dei_LegalEntityAxis=chco_CityNationalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_VA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_KY
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_StatementGeographicalAxis=stpr_OH
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |