| **Earnings Per Share**            | 6 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
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| **Earnings Per Share [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| Earnings Per Share                | Earnings Per ShareBasic net earnings (loss) per share, or basic earnings (loss) per share (“EPS”), is computed by dividing net loss to common shareholders by the weighted average number of common shares outstanding for the period.Diluted EPS reflects the potential dilution that could occur if COB's potential common stock, which consists of dilutive stock options and a common stock warrant, were issued.  As required for entities with complex capital structures, a dual presentation of basic and diluted EPS is included on the face of the income statement, and a reconciliation of the numerator and denominator of the basic EPS computation to the numerator and denominator of the diluted EPS computation is provided in this note.(dollars in thousands, except per share data) For Three Months Ended For Six Months Ended  June 30, 2014 June 30, 2013 June 30, 2014 June 30, 2013Net income (loss) $2,792 $(3,183) $4,069 $(7,779)Weighted average number of shares outstanding - basic 21,888,772 21,729,329 21,912,084 21,713,808Weighted average number of shares outstanding - diluted 21,899,994 21,729,329 21,925,798 21,713,808Net income (loss) per share - basic and diluted $0.13 $(0.15) $0.19 $(0.36)During the three and six months ended June 30, 2014, the price of the Company's common stock (as quoted on the Nasdaq Capital Market) was above the exercise price of 50,688 vested stock options, but below the price of the common stock warrant. As a result, the warrant was considered antidilutive and thus is not included in the diluted share calculation.  During the three and six months ended June 30, 2013 the price of the Company's common stock was below the exercise price of all vested stock options and the common stock warrant. In addition, as a result of the net loss for the three and six months ended June 30, 2013, all stock options and the common stock warrant were considered antidilutive and thus are not included in this calculation.  As a result, the options and warrants were considered antidilutive and thus are not included in the diluted share calculation.  For the three and six months ended June 30, 2014, there were 22,072 antidilutive shares. For the three months and six months ended June 30, 2013, there were 66,627 and 44,771 antidilutive shares, respectively. Of the antidilutive shares, the number of shares relating to stock options were 44,555 for the three months ended June 30, 2013 and 22,699 for the six months ended June 30, 2013, while the number relating to the warrant was 22,072 for all periods presented. |

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| - Definition
The entire disclosure for earnings per share.
+ References
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