BORROWED FUNDS (Details) (USD $)	9 Months Ended	12 Months Ended
Sep. 30, 2014	Dec. 31, 2014
BORROWED FUNDS (Details) [Line Items]
Number of Federal Home Loan Bank Notes		3cnob_NumberofFederalHomeLoanBankNotes
Extinguishment of Debt, Amount	$ 70,000,000us-gaap_ExtinguishmentOfDebtAmount
Long-term Line of Credit		772,000,000us-gaap_LineOfCredit
Line of Credit Facility, Remaining Borrowing Capacity		308,000,000
Long-term Debt, Weighted Average Interest Rate	3.10%
Debt Instrument Weighted Average Maturity Terms	3 years 73 days
Extinguishment of Debt Gain Loss Pretax Prepayment Penalty	4,600,000
Federal Home Loan Bank Note One [Member]
BORROWED FUNDS (Details) [Line Items]
Extinguishment of Debt, Amount		2,500,000
Debt Instrument, Maturity Date		Apr. 02, 2018
Federal Home Loan Bank Note Two [Member]
BORROWED FUNDS (Details) [Line Items]
Extinguishment of Debt, Amount		7,500,000
Debt Instrument, Maturity Date		Apr. 02, 2018
Federal Home Loan Bank Note Three [Member]
BORROWED FUNDS (Details) [Line Items]
Extinguishment of Debt, Amount		$ 5,000,000
Debt Instrument, Maturity Date		Jul. 16, 2018

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Debt instrument weighted average maturity terms.

+ References

No definition available.

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- Definition

Extinguishment of debt gain loss pretax prepayment penalty.

+ References

No definition available.

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- Definition

Number of federal home loan bank notes.

+ References

No definition available.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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Balance Type:	credit
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- Definition

Weighted average interest rate of long-term debt outstanding.

+ References

No definition available.

+ Details

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