Stock Based Compensation (Details) - Schedule of Share-based Payment Award, Unearned Shares	6 Months Ended
Jun. 30, 2018 $ / shares shares
Outstanding Beginning Balance	299,778
Awarded
Outstanding Ending Balance	251,958
Maximum [Member]
Forfeited
Vested
Outstanding Ending Balance	151,772
Unearned [Member]
Outstanding Beginning Balance	151,194
Awarded	19,614
Change in Estimate	(20,595)
Forfeited
Vested	(69,627)
Outstanding Ending Balance	80,586
Outstanding, beginning balance \| $ / shares	$ 19.19
Awarded \| $ / shares	31.25
Forfeited \| $ / shares
Vested \| $ / shares	19.46
Outstanding, ending balance \| $ / shares	$ 22.53
Restricted Stock [Member]
Outstanding Beginning Balance
Awarded	29,423
Forfeited
Vested
Outstanding Ending Balance	29,423
Outstanding, beginning balance \| $ / shares
Awarded \| $ / shares	31.35
Forfeited \| $ / shares
Vested \| $ / shares
Outstanding, ending balance \| $ / shares	$ 31.35

Gross number of share options (or share units) change in estimates during the period.

No definition available.

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Namespace Prefix:	cnob_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of options outstanding, including both vested and non-vested options.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average grant-date fair value of non-vested options forfeited.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average grant-date fair value of non-vested options outstanding.

+ References

No definition available.

+ Details

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- Definition

Number of options vested.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted average grant-date fair value of options vested.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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