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Note 2 - Summary of Significant Accounting Policies (Details Textual) shares in Thousands, $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2021 USD ($) | Sep. 30, 2021 USD ($) | Jun. 30, 2021 USD ($) | Mar. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Sep. 30, 2020 USD ($) | Jun. 30, 2020 USD ($) | Mar. 31, 2020 USD ($) | Mar. 31, 2019 USD ($) | Dec. 31, 2021 USD ($) shares | Dec. 31, 2020 USD ($) shares | Dec. 31, 2019 USD ($) shares
Revenue from Contract with Customer, Including Assessed Tax | $ 102,547 | $ 84,643 | $ 73,812 | $ 72,311 | $ 69,381 | $ 77,632 | $ 69,971 | $ 68,923 |  | $ 333,313 | $ 285,907 | $ 279,317
Book Overdrafts | 4,100 |  |  |  | 0 |  |  |  |  | 4,100 | 0 |
Workers' Compensation Liability | 1,700 |  |  |  | 1,700 |  |  |  |  | 1,700 | 1,700 |
Workers' Compensation Liability, Current | 366 |  |  |  | 237 |  |  |  |  | 366 | 237 |
Foreign Currency Transaction Gain (Loss), Realized |  |  |  |  |  |  |  |  |  | $ (500) | $ (1,100) | $ 500
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | shares |  |  |  |  |  |  |  |  |  | 0 | 0 | 0
Number of Customers with Receivable Balance in Excess of Ten Percent of Receivables |  |  |  |  |  |  |  |  |  | 0 | 1 |
Accrued Liability [Member] |  |  |  |  |  |  |  |  |  |  |  |
Workers' Compensation Liability, Current | 400 |  |  |  | 200 |  |  |  |  | $ 400 | $ 200 |
Other Long-term Liabilities [Member] |  |  |  |  |  |  |  |  |  |  |  |
Workers' Compensation Liability, Noncurrent | $ 1,300 |  |  |  | $ 1,500 |  |  |  |  | $ 1,300 | $ 1,500 |
Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Finite-Lived Intangible Asset, Useful Life (Month) |  |  |  |  |  |  |  |  |  | 7 months |  |
Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Finite-Lived Intangible Asset, Useful Life (Month) |  |  |  |  |  |  |  |  |  | 21 years |  |
Land Improvements [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  |  |  |  |  |  |  | 15 years |  |
Land Improvements [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  |  |  |  |  |  |  | 30 years |  |
Building [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  |  |  |  |  |  |  | 20 years |  |
Building [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  |  |  |  |  |  |  | 40 years |  |
Leasehold Improvements [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  |  |  |  |  |  |  | 5 years |  |
Leasehold Improvements [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  |  |  |  |  |  |  | 30 years |  |
Machinery and Equipment [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  |  |  |  |  |  |  | 3 years |  |
Machinery and Equipment [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |
Property, Plant and Equipment, Useful Life (Year) |  |  |  |  |  |  |  |  |  | 30 years |  |
Out of Period Adjustment [Member] |  |  |  |  |  |  |  |  |  |  |  |
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  | $ (1,200) |  |  |

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