v3.19.3

Note 2 - Summary of Significant Accounting Policies - Change in Fair Value of Preferred Stock Warrant Liability (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2019 | Jun. 30, 2018 | Jun. 30, 2019 | Jun. 30, 2018 | Dec. 31, 2018 | Dec. 31, 2017
Derivative [Member] |  |  |  |  |  |
Fair value, beginning of period |  |  |  |  |  |
Change in value |  | $ (60) |  | (60) | (211) |
Embedded derivative liability from the issuance of Notes |  |  |  | 496 | 864 |
Termination of the embedded derivative liability due to the extinguishment of the related Notes |  |  |  |  | (653) |
Fair value at end of period |  | 436 |  | 436 |  |
Warrant [Member] |  |  |  |  |  |
Fair value, beginning of period | 234 | 42 | 140 | 42 | 42 | 54
Preferred stock warrants - exercised |  |  |  |  |  | (8)
Change in value |  |  | 94 |  | 98 | (4)
Exchange of warrants upon Merger | (234) |  | (234) |  |  |
Fair value at end of period |  | $ 42 |  | $ 42 | $ 140 | $ 42

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- Definition Amount of transfers of financial instrument classified as a liability out of level 3 of the fair value hierarchy. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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- Definition Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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- Definition Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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