XML 51 R35.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stock-Based Compensation and Warrants (Details 3) - $ / shares | 1 Months Ended | 12 Months Ended
--- | --- | ---
Nov. 18, 2016 | Dec. 31, 2017 | Dec. 31, 2016
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] |  |  |
Closing stock price | $ 1.75 | $ 0.51 | $ 0.76
Expected dividends | 0.00% | 0.00% | 0.00%
Expected volatility | 95.00% | 80.00% | 95.00%
Risk free interest rate | 1.39% | 1.86% | 1.41%
Expected life of warrant | 5 years | 1 year 9 months 14 days | 2 years 9 months 14 days
Series A Warrants [Member] |  |  |
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] |  |  |
Closing stock price | $ 0.89 | $ 0.51 | $ 0.76
Expected dividends | 0.00% | 0.00% | 0.00%
Expected volatility | 85.00% | 80.00% | 85.00%
Risk free interest rate | 1.58% | 1.97% | 1.67%
Expected life of warrant | 4 years | 2 years 10 months 24 days | 3 years 10 months 24 days
Series B Warrants [Member] |  |  |
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] |  |  |
Closing stock price | $ 0.89 |  | $ 0.76
Expected dividends | 0.00% |  | 0.00%
Expected volatility | 85.00% |  | 90.00%
Risk free interest rate | 0.81% |  | 0.85%
Expected life of warrant | 1 year 1 month 6 days |  | 1 year

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Expected dividends to be paid to holders of the underlying shares or financial instruments (expressed as a percentage of the share or instrument's price). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsExpectedDividendRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period the instrument, asset or liability is expected to be 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 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsExpectedTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Measure of dispersion, in percentage terms (for instance, the standard deviation or variance), for a given stock price. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsExpectedVolatilityRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Risk-free interest rate assumption used in valuing an instrument. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueAssumptionsRiskFreeInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Price of a single share of a number of saleable stocks of a company. + References No definition available. + Details
Name: | us-gaap_SharePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByLiabilityClassAxis=syn_StockWarrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByLiabilityClassAxis=syn_SeriesBWarrantsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |