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Note 14 - Recent Accounting and Reporting Developments (Details Textual) - Reclassification from Cost of Sales to Other Income (Expense) [Member] | 9 Months Ended
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Sep. 30, 2018 USD ($)
Three Months Ended September 30, 2017 [Member] |
Prior Period Reclassification Adjustment | $ 0
Nine Months Ended September 30, 2017 [Member] |
Prior Period Reclassification Adjustment | $ 200,000

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- Definition The amount of a reclassification adjustment made to prior period financial statement amounts. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Details
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Namespace Prefix: |
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Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |