| Schedule of Long-term Debt Instruments [Table Text Block] |
| | A summary of long-term debt is as follows (in thousands): | | | | | | | | | | | | | | | | | June 30, | | December 31, | | | | | 2012 | | 2011 | | Senior secured debt (see below): | | | | | | | | Senior variable-rate term note | $ | 42,500 | | $ | 45,000 | | | Senior variable-rate revolving note | | 126,500 | | | 128,700 | | Total senior secured debt | | 169,000 | | | 173,700 | | Unsecured notes payable | | 2,623 | | | 2,470 | | Capital lease obligations | | 459 | | | 221 | | | | | | 172,082 | | | 176,391 | | Less current portion | | 7,831 | | | 7,667 | | Long-term debt, less current portion | $ | 164,251 | | $ | 168,724 |
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