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Note 2 - Investments - Current Investments (Details) - USD ($) $ in Thousands | Dec. 31, 2016 | Dec. 31, 2015
--- | --- | ---
Available for sale securities, amortized cost | $ 29,166 |
Available for sale securities, unrealized loss | (49) |
Available for sale securities, fair market value | 29,117 |
Corporate Bond Securities [Member] |  |
Available for sale securities, amortized cost | 22,100 |
Available for sale securities, unrealized loss | (46) |
Available for sale securities, fair market value | 22,054 |
Municipal Bonds [Member] |  |
Available for sale securities, amortized cost | 3,727 |
Available for sale securities, unrealized loss | (1) |
Available for sale securities, fair market value | 3,726 |
US Government Agencies Debt Securities [Member] |  |
Available for sale securities, amortized cost | 3,339 |
Available for sale securities, unrealized loss | (2) |
Available for sale securities, fair market value | $ 3,337 |

X
- Definition Amount before tax of current unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References No definition available. + Details
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X
- Definition This item represents the current cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
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- Definition Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26626-111562 + Details
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- Details
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Data Type: | na
Balance Type: |
Period Type: |

X
- Details
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Balance Type: |
Period Type: |

X
- Details
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