v3.8.0.1

Note 12 - Stock-based Compensation - Stock Options Outstanding, Vested and Exercisable (Details) - $ / shares | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016
Exercise Price Range, Lower Range Limit (in dollars per share) |  |
Exercise Price Range, Upper Range Limit (in dollars per share) |  |
Number of Stock Options Outstanding (in shares) | 8,455,098 | 6,307,756
Weighted-average Remaining Contractual LIfe (Year) | 7 years 36 days |
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share) | $ 4.25 | $ 5
Shares Subject to Stock Options (in shares) | 4,529,174 |
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share) | $ 5.11 |
Exercise Price Range 1 [Member] |  |
Exercise Price Range, Lower Range Limit (in dollars per share) | 1.20 |
Exercise Price Range, Upper Range Limit (in dollars per share) | $ 2.30 |
Number of Stock Options Outstanding (in shares) | 105,900 |
Weighted-average Remaining Contractual LIfe (Year) | 8 years 146 days |
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share) | $ 2.13 |
Shares Subject to Stock Options (in shares) | 38,400 |
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share) | $ 1.84 |
Exercise Price Range 2 [Member] |  |
Exercise Price Range, Lower Range Limit (in dollars per share) | 2.40 |
Exercise Price Range, Upper Range Limit (in dollars per share) | $ 3.77 |
Number of Stock Options Outstanding (in shares) | 5,592,633 |
Weighted-average Remaining Contractual LIfe (Year) | 7 years 255 days |
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share) | $ 3.10 |
Shares Subject to Stock Options (in shares) | 1,948,300 |
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share) | $ 3.17 |
Exercise Price Range 3 [Member] |  |
Exercise Price Range, Lower Range Limit (in dollars per share) | 3.92 |
Exercise Price Range, Upper Range Limit (in dollars per share) | $ 6.60 |
Number of Stock Options Outstanding (in shares) | 2,060,565 |
Weighted-average Remaining Contractual LIfe (Year) | 5 years 255 days |
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share) | $ 5.45 |
Shares Subject to Stock Options (in shares) | 1,880,190 |
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share) | $ 5.36 |
Exercise Price Range 4 [Member] |  |
Exercise Price Range, Lower Range Limit (in dollars per share) | 8.18 |
Exercise Price Range, Upper Range Limit (in dollars per share) | $ 10.55 |
Number of Stock Options Outstanding (in shares) | 696,000 |
Weighted-average Remaining Contractual LIfe (Year) | 6 years 73 days |
Options Outstanding, Weighted-average Exercise Price Per Share (in dollars per share) | $ 10.28 |
Shares Subject to Stock Options (in shares) | 662,284 |
Options Vested and Exercisable, Weighted-average Exercise Price Per Share (in dollars per share) | $ 10.28 |

X
- Definition The weighted average exercise price of exercisable share options (fully vested and expected to vest) that may be converted as of the balance sheet date. + References No definition available. + Details
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- Definition Number of options outstanding, including both vested and non-vested options. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under 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)(i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Number of fully vested and expected to vest exercisable options that may be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur. + 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 (e)(2) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. + 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 (g) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. + 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 (g) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + 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 (e)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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