Stock-Based Compensation (Details) - Schedule of unearned performance unit awards - Jun. 30, 2015 - $ / shares	Total
Schedule of unearned performance unit awards [Abstract]
Stock based compensation, Unearned Shares	94,585
Stock based compensation, Unearned Weighted-Average Grant Date Fair Value	$ 19.46

Stock based compensation, Unearned Weighted-Average Grant Date Fair Value.

No definition available.

Name:	cnob_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsUnearnedWeightedAverageGrantDateFairValue
Namespace Prefix:	cnob_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant