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Note 12 - Employee Benefits - Non-vested Option Awards Activity (Details) - $ / shares | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Granted (in shares) | 136,501 |  |
Granted (in dollars per share) | $ 4.34 | $ 3.17 | $ 3.58
Forfeited (in shares) | (16,836) |  |
Service Based Options [Member] |  |  |
Balance at beginning of period, nonvested (in shares) | 444,476 |  |
Weighted average grant date fair value, beginning of period, nonvested (in dollars per share) | $ 3.46 |  |
Nonvested Contractual Life (Year) | 5 years 36 days | 5 years |
Granted (in shares) | 136,501 |  |
Granted (in dollars per share) | $ 4.34 |  |
Granted (Year) | 6 years 255 days |  |
Vested (in shares) | (151,912) |  |
Vested (in dollars per share) | $ 3.39 |  |
Vested (Year) | 3 years 146 days |  |
Forfeited (in shares) | (15,837) |  |
Forfeited (in dollars per share) | $ 3.19 |  |
Forfeited (Year) | 4 years 109 days |  |
Balance at end of period, nonvested (in shares) | 413,228 | 444,476 |
Weighted average grant date fair value, end of period, nonvested (in dollars per share) | $ 3.79 | $ 3.46 |

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- Definition Sharebased compensation arrangement by sharebased payment award options forfeited weighted average remaining contractual term2. + References No definition available. + Details
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- Definition The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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