Commitments (Details 1) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Commitments to extend credit:
Fixed rate	$ 14,519	$ 14,551
Variable rate	39,342	48,184
Standby letters of credit	$ 443	$ 477

Commitments to extend credit standby letters of credit.

No definition available.

Name:	cldb_CommitmentsToExtendCreditStandbyLettersOfCredit
Namespace Prefix:	cldb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant