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Note 2 - Summary of Significant Accounting Policies (Details Textual) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 USD ($) shares | Dec. 31, 2017 USD ($) shares | Dec. 31, 2016 USD ($) shares | Jan. 01, 2019 USD ($)
Book Overdrafts | $ 0 | $ 0 |  |
Workers' Compensation Liability | 2,700,000 | 3,700,000 |  |
Workers' Compensation Liability, Current | 452,000 | 422,000 |  |
Foreign Currency Transaction Gain (Loss), Realized | $ (400,000) | $ (200,000) | $ 100,000 |
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares | 63,000 | 196,000 | 198,000 |
Number of Customers with Receivable Balance in Excess of Ten Percent of Receivables | 1 | 2 |  |
Subsequent Event [Member] | Accounting Standards Update 2016-02 [Member] |  |  |  |
Operating Lease, Right-of-Use Asset |  |  |  | $ 8,000,000
Operating Lease, Liability, Total |  |  |  | $ 8,000,000
Reclassification from Cost of Sales to Other Income Expense [Member] |  |  |  |
Prior Period Reclassification Adjustment |  | $ 0 | $ 400,000 |
Performance Shares [Member] |  |  |  |
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | shares | 39,000 |  |  |
Accrued Liability [Member] |  |  |  |
Workers' Compensation Liability, Current | $ 500,000 | 400,000 |  |
Other Long-term Liabilities [Member] |  |  |  |
Workers' Compensation Liability, Noncurrent | $ 2,200,000 | $ 3,300,000 |  |
Minimum [Member] |  |  |  |
Finite-Lived Intangible Asset, Useful Life | 330 days |  |  |
Maximum [Member] |  |  |  |
Finite-Lived Intangible Asset, Useful Life | 15 years |  |  |
Land Improvements [Member] | Minimum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life | 15 years |  |  |
Land Improvements [Member] | Maximum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life | 30 years |  |  |
Building [Member] | Minimum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life | 20 years |  |  |
Building [Member] | Maximum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life | 40 years |  |  |
Machinery and Equipment [Member] | Minimum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life | 3 years |  |  |
Machinery and Equipment [Member] | Maximum [Member] |  |  |  |
Property, Plant and Equipment, Useful Life | 30 years |  |  |

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