| **Short-Term Borrowings and Long-Term Debt** | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      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| **Debt Disclosure [Abstract]**               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               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| Short-Term Borrowings and Long-Term Debt     | Short-Term Borrowings and Long-Term DebtThe following table stratifies COB’s borrowings as short-term and long-term at the periods indicated.   December 31,(dollars in thousands) 2013 2012  Balance Rate Balance RateShort-term borrowings:        Retail customer repurchase agreements $6,917 0.21% $8,675 0.19%Total short-term borrowings $6,917   $8,675  Long-term debt:        Federal Home Loan Bank advances $73,283 1.80 $58,328 2.62Long-term notes payable 5,263 1.41 — —Junior subordinated debt 56,702 1.77 56,702 1.83Total long-term debt $135,248   $115,030  Retail Repurchase Agreements and Federal Funds PurchasedFunds are borrowed on an overnight basis through retail repurchase agreements with bank customers and federal funds purchased from other financial institutions. Retail repurchase agreement borrowings are collateralized by securities of the U.S. Treasury and U.S. Government agencies and corporations.At December 31, 2013, the Bank had no borrowings at the Federal Reserve Bank.Information concerning retail repurchase agreements and federal funds purchased is as follows: (dollars in thousands) 201320122011   RetailRepurchaseAgreements RetailRepurchaseAgreements RetailRepurchaseAgreements Balance at December 31 $6,917 $8,675 $8,838 Average balance during the year 9,852 9,861 8,973 Maximum month end balance 13,064 12,720 10,917 Weighted average interest rate:       At December 31 0.21% 0.19% 0.42% During the year 0.21 0.29 0.58 Federal Home Loan Bank (“FHLB”) AdvancesAt December 31, 2013, the Bank had an available borrowing capacity of $31.8 million and access to additional borrowings of $301.8 million by pledging additional collateral with the FHLB.  At December 31, 2013, outstanding FHLB advances under the current line amounted to $73.3 million and were at interest rates ranging from 0.93% to 6.15%. These borrowings are secured by collateral on qualifying mortgage loans and, as required, by other qualifying collateral. At December 31, 2012, FHLB advances amounted to $58.3 million and were at interest rates ranging from 2.33% to 6.15%. At December 31, 2013, the scheduled maturities of FHLB advances payable over the next five years and thereafter, certain of which are convertible to a variable rate at the option of the FHLB before scheduled maturity, are as follows:(dollars in thousands) Twelve Months Ended December 31, 2014$5,00020153,00020165,00020175,00020185,2832019 and thereafter50,000Total FHLB advances$73,283Long-term debt included of the following advances from the FHLB at the periods indicated. (dollars in thousands)          December 31,Maturity Interest Rate 2013 2012December 29, 2014 3.3125% $5,000 $5,000September 8, 2015 3.7100% 3,000 3,000September 27, 2016 0.9300% 5,000 —September 27, 2017 1.4200% 5,000 —March 19, 2018 2.8100% — 10,000July 16, 2018 2.4300% — 20,000July 18, 2018 2.3300% — 20,000August 27, 2018 6.1500% 283 328September 27, 2018 1.8400% 5,000 —June 15, 2020 1.6247% 50,000 —    $73,283 $58,328During the second quarter of 2013 we restructured $50 million of Federal Home Loan Bank advances from fixed rate to floating rate, which we expect to further reduce interest costs. The restructured advances, per ASC 470-50 "Debt - Modifications and Extinguishments," are not substantially different than the prior advances so there was no debt extinguishment. Subordinated DebtOn October 21, 2011, as part of the Recapitalization, the Bank settled $2.5 million aggregate principal amount of subordinated debt outstanding and held by SunTrust Bank for cash in an amount equal to the sum of 35% of the principal amount thereof plus 100% of the unpaid and accrued interest thereon as of the closing date. The Bank recognized a gain of approximately $1.6 million as part of the settlement. During 2010, we converted $7.5 million of subordinated debt into $7.5 million of nonvoting, nonconvertible, nonredeemable cumulative preferred stock, and converted an additional $5.0 million during the first quarter of 2011. On October 21, 2011, the Bank repurchased from SunTrust the shares of nonvoting, nonconvertible, nonredeemable cumulative preferred stock of the Bank held by SunTrust and having an aggregate liquidation preference of $12.5 million for cash in an amount equal to the sum of 25% of the aggregate liquidation preference plus 100% of the unpaid and accrued dividends thereon as of the closing date. The Bank recorded an increase in retained earnings of approximately $9.4 million in connection with this settlement. Thus, as of October 21, 2011, the Bank no longer had any outstanding subordinated debt.Long-term Notes PayableThe amount reported as long-term notes payable consists of a note, secured by Bank stock, payable to Howe Barnes Hoefer & Arnett, Inc. ("Howe Barnes") in connection with the settlement of legal proceedings between Howe Barnes and the Bank. The note bears an imputed interest rate of 1.41% and matures in 2016.Junior Subordinated Deferrable Interest DebenturesCOB has Junior Subordinated Deferrable Interest Debentures or Junior Subordinated Debentures outstanding. Two issues of Junior Subordinated Debentures resulted from funds invested from the sale of trust preferred securities by FNB United Statutory Trust I (“FNB Trust I”) and by FNB United Statutory Trust II (“FNB Trust II”), which are owned by COB. Two additional issues of Junior Subordinated Debentures were acquired on April 28, 2006 as a result of COB’s merger with Integrity Financial Corporation. These acquired issues resulted from funds invested from the sale of trust preferred securities by Catawba Valley Capital Trust I (“Catawba Trust I”) and by Catawba Valley Capital Trust II (“Catawba Trust II”), which were owned by Integrity and acquired by COB in the merger. COB initiated the redemption of the securities issued by Catawba Valley Trust I as of December 30, 2007 and that trust was subsequently dissolved.COB fully and unconditionally guarantees the preferred securities issued by each trust through the combined operation of the debentures and other related documents. Obligations under these guarantees are unsecured and subordinate to senior and subordinated indebtedness of COB. The preferred securities qualify as Tier 1 and Tier 2 capital for regulatory capital purposes.During the second quarter of 2010, COB suspended payment of interest on junior subordinated debt for liquidity purposes. The associated interest expense on junior subordinated debt has been fully accrued and is included in the Consolidated Statements of Operations. Payment of this interest was made in connection with the Recapitalization in order to be able to redeem the CommunityOne preferred stock issued to SunTrust Bank, described above. COB again suspended payment of interest on the Junior Subordinated Debentures as of the first quarter 2012.Information concerning the Junior Subordinated Debentures is as follows at the periods indicated. (dollars in thousands)   Commencement           Stated of Early As of December 31,   Maturity Redemption 2013 2012 Issuer Date Period Principal Unpaid Interest Principal Unpaid InterestInterest RateFNB Trust I 12/15/2035 12/15/2010 $20,619 $753 $20,619 $4033 month LIBOR + 1.37% =1.616% at 12/31/13FNB Trust II 6/30/2036 6/30/2011 30,928 1,078 30,928 5673 month LIBOR + 1.32% =1.566% at 12/31/13Catawba Trust II 12/30/2032 12/30/2007 5,155 404 5,155 2043 month LIBOR + 3.35% =3.596% at 12/31/13Total Junior Subordinated Debentures     $56,702 $2,235 $56,702 $1,174  |

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| - Definition
The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19,20,22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
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