Commitments (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Commitments to extend credit:
Fixed rate	$ 8,099	$ 7,725
Variable rate	48,850	52,026
Standby letters of credit	$ 652	$ 714

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