Note 4 - Inventory (Details) - Carrying Values of Inventory - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| At average cost (approximates current cost) | ||
| Finished goods | $ 35,517 | $ 25,369 |
| Work in process | 1,695 | 2,391 |
| Raw materials and supplies | 31,247 | 25,935 |
| Total inventories at weighted average cost | 68,459 | 53,695 |
| LIFO reserve | (3,502) | (8,342) |
| Total inventories | $ 64,957 | $ 45,353 |