| **Common Dividends**     | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
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| **Dividends [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| Common Dividends         | Common DividendsCOB is a legal entity separate and distinct from its banking and other subsidiaries and has in the past relied on dividends from the Bank as its primary source of liquidity. The Bank currently is restricted from paying dividends if it is not in compliance with its OCC-approved business plan, and COB would need to obtain prior FRBR approval to pay a dividend.  There also are limitations and requirements imposed by applicable law and regulation on the payment of dividends by the Bank to COB, as well as by COB to its shareholders.  COB did not declare any dividends with respect to its common stock in 2013. |

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| - Definition
Common Stock [Text Block]
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No definition available.
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| - Details**Name:**us-gaap_DividendsAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |