| Valuation Allowances and Reserves [Table Text Block] |
| SCHEDULE II: VALUATION AND QUALIFYING ACCOUNTS | |
| (in thousands) | |
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| | | | | | | Additions | | | | | | | | | |
| | | Balance at | | | Charged as a | | | | | | | Balance at | |
| | | Beginning of | | | Reduction to | | | | | | | End of | |
| Description | | Period | | | Revenue | | | Deductions* | | | Period | |
| Sales & return allowances, discounts, chargebacks and rebates: | | | | | | | | | | | | | | | | |
| Year ended December 31, 2021 | | $ | 668 | | | $ | 1,012 | | | $ | (900 | ) | | $ | 780 | |
| Year ended December 31, 2020 | | $ | 161 | | | $ | 645 | | | $ | (138 | ) | | $ | 668 | |
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| * Deductions to sales discounts and allowances relate to discounts or allowances actually taken or paid. | |
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