v3.8.0.1

Note 2 - Investments and Fair Value Measurement (Tables) | 12 Months Ended
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Dec. 31, 2017
Notes Tables |
Cash, Cash Equivalents and Investments [Table Text Block] |
|  | As of December 31 , 201 7 |
|  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
Cash and cash equivalents: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash |  | $ | 29,765 |  |  | $ | — |  |  | $ | — |  |  | $ | 29,765 |
U.S. government agency securities |  |  | 23,137 |  |  |  | — |  |  |  | — |  |  |  | 23,137 |
Total cash and cash equivalents |  |  | 52,902 |  |  |  | — |  |  |  | — |  |  |  | 52,902 |
Marketable securities : |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
U.S. government agency securities |  | $ | 7,567 |  |  | $ | — |  |  | $ | — |  |  | $ | 7,567 |
Total marketable securities |  |  | 7,567 |  |  |  | — |  |  |  | — |  |  |  | 7,567 |
Total cash, cash equivalents and investments |  | $ | 60,469 |  |  | $ | — |  |  | $ | — |  |  | $ | 60,469 |
|  | As of December 31 , 2016 |
|  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
Cash and cash equivalents: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cash |  | $ | 49,833 |  |  | $ | — |  |  | $ | — |  |  | $ | 49,833 |
U.S. government agency securities |  |  | 30,474 |  |  |  | 3 |  |  |  | — |  |  |  | 30,477 |
Total cash and cash equivalents |  |  | 80,307 |  |  |  | 3 |  |  |  | — |  |  |  | 80,310 |
Total cash, cash equivalents and investments |  | $ | 80,307 |  |  | $ | 3 |  |  | $ | — |  |  | $ | 80,310 |
Fair Value Measurements, Recurring and Nonrecurring [Table Text Block] |
|  | As of December 31 , 201 7 |
|  | Fair Value |  |  | Level I |  |  | Level II |  |  | Level III |
Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
U.S. government agency obligations |  | $ | 30,704 |  |  | $ | — |  |  | $ | 30,704 |  |  | $ | — |
Total assets measured at fair value |  | $ | 30,704 |  |  | $ | — |  |  | $ | 30,704 |  |  | $ | — |
Liabilities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Contingent put option liability |  | $ | 207 |  |  | $ | — |  |  | $ | — |  |  | $ | 207 |
Total liabilities measured at fair value |  | $ | 207 |  |  | $ | — |  |  | $ | — |  |  | $ | 207 |
|  | As of December 31 , 2016 |
|  | Fair Value |  |  | Level I |  |  | Level II |  |  | Level III |
Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
U.S. government agency obligations |  | $ | 30,477 |  |  | $ | — |  |  | $ | 30,477 |  |  | $ | — |
Total assets measured at fair value |  | $ | 30,477 |  |  | $ | — |  |  | $ | 30,477 |  |  | $ | — |
Liabilities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
PIPE warrants |  | $ | 288 |  |  |  | — |  |  |  | — |  |  | $ | 288 |
Contingent put option liability |  |  | 124 |  |  |  | — |  |  |  | — |  |  |  | 124 |
Total liabilities measured at fair value |  | $ | 412 |  |  | $ | — |  |  | $ | — |  |  | $ | 412 |
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] |
|  | Year Ended December 31, 201 7 |
Fair value —beginning of period |  | $ | 412 |
Expiration of fair value of PIPE warrants |  |  | (288 | )
Change in fair value of contingent put option associated with Original Loan Agreement |  |  | 83 |
Fair value —end of period |  | $ | 207 |
|  | Year Ended December 31, 201 6 |
Fair value —beginning of period |  | $ | 1,179 |
Change in fair value of PIPE warrants |  |  | (625 | )
Change in fair value of contingent put option associated with Original Loan Agreement |  |  | (142 | )
Fair value —end of period |  | $ | 412 |

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- Definition Tabular disclosure of financial instruments measured at fair value, including those classified in shareholders' equity measured on a recurring or nonrecurring basis. Disclosures include, but are not limited to, fair value measurements recorded and the reasons for the measurements, level within the fair value hierarchy in which the fair value measurements are categorized and transfers between levels 1 and 2. Nonrecurring fair value measurements are those that are required or permitted in the statement of financial position in particular circumstances. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19279-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2C -URI http://asc.fasb.org/extlink&oid=66048111&loc=SL7498348-110258 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19190-110258 + Details
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- Definition Tabular disclosure of the fair value measurement of liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets), and gains or losses recognized in other comprehensive income (loss) and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs) by class of liability. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19279-110258 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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