Recent Accounting Pronouncements (Narrative) (Details) $ in Thousands	3 Months Ended
Mar. 31, 2020 USD ($)
New Accounting Pronouncement Or Change In Accounting Principle, Effect Of Adoption, Quantification	$ (2,335)
Receivables Acquired with Deteriorated Credit Quality [Domain]
New Accounting Pronouncement Or Change In Accounting Principle, Effect Of Adoption, Quantification	$ 2,700

New Accounting Pronouncement, Effect Of Adoption, Quantification

No definition available.

Name:	chco_NewAccountingPronouncementEffectOfAdoptionQuantification
Namespace Prefix:	chco_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration