Premises and Equipment (Details) - Schedule of Capital Lease in Premises and Equipment - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule of Capital Lease in Premises and Equipment [Abstract]
Capital Lease	$ 3,408	$ 3,422
Less: accumulated amortization	1,526	1,369
Lease in premises and equipment	$ 1,882	$ 2,053

Capital lease in premises and equipment excluding accumulated amortization.

No definition available.

Name:	cnob_CapitalLeaseInPremisesAndEquipmentExcludingAccumulatedAmortization
Namespace Prefix:	cnob_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant