Additional number of securities into which the class of warrant or right may be converted.

No definition available.

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- Definition

Number of shares to be issued for each share of convertible preferred stock that is converted.

+ References

No definition available.

+ Details

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- Definition

The number of warrants issued during the year.

+ References

No definition available.

+ Details

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- Definition

Per share conversion price of convertible preferred stock.

+ References

No definition available.

+ Details

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- Definition

Stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

+ References

No definition available.

+ Details

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- Definition

The percentage of exercise price of warrant on public offering price.

+ References

No definition available.

+ Details

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Namespace Prefix:	syn_
Data Type:	num:percentItemType
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- Definition

It represents the expiration date of warrant.

+ References

No definition available.

+ Details

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Namespace Prefix:	syn_
Data Type:	xbrli:dateItemType
Balance Type:	na
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- Definition

Represents the warrant term.

+ References

No definition available.

+ Details

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Namespace Prefix:	syn_
Data Type:	xbrli:durationItemType
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- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

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- Definition

Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(2))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Period Type:	instant

- Definition

Face amount or stated value per share of common stock.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	na
Period Type:	duration

- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Gross number of share options (or share units) granted during the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
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- Details

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Subsequent Events (Details Textual) - USD ($)			9 Months Ended
Subsequent Events (Details Textual) - USD ($)	Oct. 15, 2018	Oct. 10, 2018	Sep. 30, 2018	Sep. 30, 2017	Jul. 28, 2018	Dec. 31, 2017
Proceeds from Issuance or Sale of Equity			$ 6,422,000	$ 6,358,000
Common Stock, Par or Stated Value Per Share			$ 0.001		$ 0.001	$ 0.001
Subsequent Event [Member] \| October 2018 Warrants [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights		2,428,825
Class of Warrant or Right Additional Number of Securities Called by Warrants or Rights		1,807,826
Warrant Exercise Price Percentage on Public Offering Price		120.00%
Warrant Expiration Date		Oct. 15, 2023
Subsequent Event [Member] \| Underwritten Public Offering [Member]
Proceeds from Issuance or Sale of Equity	$ 18.6
Convertible Preferred Stock Shares to be Issued upon Conversion	13,672,173
Subsequent Event [Member] \| Underwritten Public Offering [Member] \| October 2018 Warrants [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 1.38
Warrant Term	5 years
Sale of Stock, Price Per Share	$ 1.15
Number of Warrants Issued	13,672,173
Subsequent Event [Member] \| Over-Allotment Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross		2,428,825
Class A [Member] \| Subsequent Event [Member] \| Underwritten Public Offering [Member]
Sale of Stock, Number of Shares Issued in Transaction	2,520,000
Common Stock, Par or Stated Value Per Share	$ 0.001
Class B Units [Member] \| Subsequent Event [Member] \| Underwritten Public Offering [Member]
Sale of Stock, Number of Shares Issued in Transaction	15,723
Sale of Stock, Price Per Share	$ 1,000
Series B Preferred Stock [Member] \| Subsequent Event [Member] \| Underwritten Public Offering [Member]
Preferred Stock Stated Value Per Share	1,000
Preferred Stock Convertible Conversion Price	$ 1.15