Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Contract Amount [Abstract]
Loan Commitments	$ 72,918cban_LoanCommitmentContractAmount	$ 68,742cban_LoanCommitmentContractAmount
Letters of Credit	$ 1,663	$ 1,762
Expiration period of letter of credit issued	1 year

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant