Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Allowance for Doubtful Accounts Receivable | $ 0 | $ 0 | |
| Income Tax Contingency | 50.00% | ||
| Unrecognized Tax Benefits | $ 0 | $ 0 | |
| Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | |||
| Concentration Risk, Percentage | 26.50% | 23.70% | 18.80% |
| Number of Customers | 2 | ||
| Minimum [Member] | |||
| Notes Receivable Installment Term | 10 years | ||
| X | ||||||||||
- Definition The percentage contingency associated with income taxes. No definition available.
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| X | ||||||||||
- Definition The term associated with notes receivable. No definition available.
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| X | ||||||||||
- Definition Element represents the number of customers. No definition available.
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| X | ||||||||||
- Definition For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of unrecognized tax benefits. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Details
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| X | ||||||||||
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