XML 64 R54.htm IDEA: XBRL DOCUMENT
v3.22.2

Common and Preferred Stock (Details) |  |  |  |  |  | 3 Months Ended | 6 Months Ended | 12 Months Ended |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jan. 27, 2021 $ / shares | Nov. 16, 2020 $ / shares shares | Oct. 15, 2018 USD ($) $ / shares shares | Oct. 10, 2018 shares | Sep. 11, 2017 USD ($) D $ / shares shares | Jun. 30, 2022 USD ($) shares | Jun. 30, 2021 USD ($) | Mar. 31, 2021 USD ($) shares | Mar. 31, 2020 USD ($) | Jun. 30, 2022 USD ($) shares | Jun. 30, 2021 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) | Aug. 03, 2022 $ / shares | Feb. 28, 2021 shares | Jan. 31, 2021 shares | Jan. 26, 2021 | Nov. 15, 2020 $ / shares | Oct. 31, 2018 $ / shares | Dec. 31, 2017 USD ($) | Aug. 05, 2016
Proceeds from Issuance or Sale of Equity | $ |  |  | $ 18,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues |  |  |  |  |  | 0 |  | 7,900,000 |  | 0 |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Par or Stated Value Per Share | $ / shares |  | $ 0.001 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exercise price per warrant | $ / shares |  | $ 6.90 | $ 13.80 |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 13.80 | $ 6.90 |  |
Effect of Warrant exercise price adjustment | $ |  |  |  |  |  |  |  |  |  |  |  | $ 900,000 | $ 880,000 |  |  |  |  |  |  |  |
Common stock issued upon conversion |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 899,677 | 899,677 |  |  |  |  |
Proceeds from Issuance of Common Stock | $ |  |  |  |  |  |  |  | $ 66,000,000.0 |  | $ 0 | $ 65,960,000 |  |  |  |  |  |  |  |  |  |
Common Stock, Discount on Shares | $ |  |  |  |  |  | $ 200,000,000 |  |  |  | $ 200,000,000 |  |  |  |  |  |  |  |  |  |  |
Subsequent Event |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exercise price per warrant | $ / shares |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 6.90 |  |  |  |  |  |  |
Over-Allotment Option [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues |  | 242,883 |  | 242,883 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights |  | 242,883 |  | 242,883 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Issue of warrants to purchase common stock |  | 180,783 |  | 180,783 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fbr Capital Markets Co [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Brokerage Commission percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.00%
Warrant |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights |  |  |  |  |  |  |  | 1,165,575 |  |  |  |  |  |  |  |  |  |  |  |  |
Conversion of Stock, Shares Converted |  |  | 1,367,218 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exercise price per warrant | $ / shares |  | $ 6.90 | $ 6.90 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Series A Preferred Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock Conversion Price Per Share | $ / shares | $ 189 |  |  |  | $ 5.40 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Accretion of Preferred Stock Deemed Dividend | $ |  |  |  |  |  |  |  | $ 7,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Dividend Rate, Percentage |  |  |  |  | 2.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Convertible, Conversion Price, Increase | $ / shares | 189.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Convertible, Conversion Price, Decrease | $ / shares | $ 15.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Convertible Preferred Stock, Terms of Conversion |  |  |  |  | (i) a 19.99% blocker provision to comply with NYSE American Listing Rules, (ii) if so elected by the Investor, a 4.99% blocker provision that will prohibit beneficial ownership of more than 4.99% of the outstanding shares of the Company’s common stock or voting power at any time, and (iii) applicable regulatory restrictions. |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Convertible, Threshold Trading Days | D |  |  |  |  | 20 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Convertible, Threshold Consecutive Trading Days | D |  |  |  |  | 30 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable, Amount Per Share | $ / shares |  |  |  |  | $ 70.00 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Adjustments to Additional Paid in Capital, Stock Split | $ |  |  |  |  | $ 7,875.00 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock Redemption Discount | $ |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 6,900,000 |
Percentage of stated dividend rate |  |  |  |  |  |  |  |  |  | 2.00% |  |  |  |  |  |  |  |  |  |  |
Preferred stock accrued dividends | $ |  |  |  |  |  | $ 0 | $ 0 | $ 24,000 | $ 62,000 |  | 24,000 |  |  |  |  |  |  |  |  |  |
Maximum percentage | 9.99% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.99% |  |  |  |
Number of common shares issued for convertible preferred stock |  |  |  |  |  |  |  | 900,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock Shares Converted |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Shares Outstanding |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 12,000 | 12,000 |  |  |  |  |
Estimated fair value of inducement consideration | $ |  |  |  |  |  |  |  | $ 7,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Series A Preferred Stock [Member] | Private Placement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues |  |  |  |  | 12,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Par or Stated Value Per Share | $ / shares |  |  |  |  | $ 0.001 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from Issuance of Convertible Preferred Stock | $ |  |  |  |  | $ 12,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Sale of Stock, Consideration Received Per Transaction | $ |  |  |  |  | $ 10 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Series B Preferred Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues |  |  | 15,723 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Value, Issued for Services | $ |  |  | $ 1,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred Stock Conversion Price Per Share | $ / shares |  |  | $ 11.50 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights |  |  | 1,367,218 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Conversion of Stock, Shares Converted |  |  | 1,367,218 |  |  | 0 |  | 398 |  | 0 |  |  |  |  |  |  |  |  |  |  |
Accretion of Preferred Stock Deemed Dividend | $ |  |  |  |  |  |  |  | $ 1,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock accrued dividends | $ |  |  |  |  |  | $ 0 | $ 0 |  |  |  | $ 1,497,000 |  |  |  |  |  |  |  |  |  |
Common Class A [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues |  |  | 252,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Warrant Term |  |  | 5 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition This element represents the amount of accretion of the Series B preferred stock deemed dividend. + References No definition available. + Details
Name: | syn_AccretionOfPreferredStockDeemedDividend
Namespace Prefix: | syn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of beneficial ownership. + References No definition available. + Details
Name: | syn_BeneficialOwnershipPercentage
Namespace Prefix: | syn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represent that percentage of commission revenue from buying and selling securities on behalf of customers. + References No definition available. + Details
Name: | syn_BrokerageCommissionPercentage
Namespace Prefix: | syn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of Estimated Fair Value of Inducement Consideration. + References No definition available. + Details
Name: | syn_EstimatedFairValueOfInducementConsideration
Namespace Prefix: | syn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition It represent additional of warrant to purchase of common stock + References No definition available. + Details
Name: | syn_IssueOfWarrantsToPurchaseCommonStock
Namespace Prefix: | syn_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents the percentage of stated dividend rate + References No definition available. + Details
Name: | syn_PercentageOfStatedDividendRate
Namespace Prefix: | syn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity can be converted. + References No definition available. + Details
Name: | syn_PreferredStockConversionPricePerShare
Namespace Prefix: | syn_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The no of shares converted into common stock + References No definition available. + Details
Name: | syn_PreferredStockSharesConverted
Namespace Prefix: | syn_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount represents the effect of warrant exercise price adjustment. + References No definition available. + Details
Name: | syn_WarrantExercisePriceAdjustment
Namespace Prefix: | syn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Represents the warrant term. + References No definition available. + Details
Name: | syn_WarrantTerm
Namespace Prefix: | syn_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of decrease in additional paid in capital (APIC) resulting from a stock split in which per-share par value or stated value is not changed proportionately. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770 + Details
Name: | us-gaap_AdjustmentsToAdditionalPaidInCapitalStockSplit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- 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://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644 + Details
Name: | us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Discount on common shares, or any unamortized balance thereof, shown separately as a deduction from the applicable account(s) as circumstances require. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.4-07) -URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187103-122770 + Details
Name: | us-gaap_CommonStockDiscountOnShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The number of shares converted in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=126999549&loc=d3e4313-108586 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126999549&loc=d3e4304-108586 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=126999549&loc=d3e4332-108586 + Details
Name: | us-gaap_ConversionOfStockSharesConverted1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares issued for each share of convertible preferred stock that is converted. + 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(27)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: 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(28)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 16 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496180-112644 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21506-112644 + Details
Name: | us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Description of conversion terms for preferred stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 8 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21538-112644 Reference 2: 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(28)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 7 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21521-112644 Reference 4: 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(27)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21506-112644 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644 + Details
Name: | us-gaap_ConvertiblePreferredStockTermsOfConversion
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentConvertibleThresholdTradingDays
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The per share amount of a dividend declared, but not paid, as of the financial reporting date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126999549&loc=d3e4304-108586 + Details
Name: | us-gaap_DividendsPayableAmountPerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Per share decrease in conversion price of convertible preferred stock. Excludes change due to standard antidilution provision. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 16 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496180-112644 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644 + Details
Name: | us-gaap_PreferredStockConvertibleConversionPriceDecrease
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Per share increase in conversion price of convertible preferred stock. Excludes change due to standard antidilution provision. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 16 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496180-112644 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644 + Details
Name: | us-gaap_PreferredStockConvertibleConversionPriceIncrease
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Discount on preferred shares, or any unamortized balance thereof, shown separately as a deduction from the applicable account(s) as circumstances require. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.4-07) -URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187103-122770 + Details
Name: | us-gaap_PreferredStockDiscountOnShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The percentage rate used to calculate dividend payments on preferred stock. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 13 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644 + Details
Name: | us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of preferred stock dividends that is an adjustment to net income apportioned to common stockholders. + References No definition available. + Details
Name: | us-gaap_PreferredStockDividendsIncomeStatementImpact
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. + 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(28)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 13 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126973232&loc=SL123496158-112644 + Details
Name: | us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. + 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(28)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow from the additional capital contribution to the entity. + 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 https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The cash inflow from issuance of preferred stocks identified as being convertible into another form of financial instrument, typically the entity's common stock. + 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 https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfConvertiblePreferredStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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 https://asc.fasb.org/extlink&oid=126954810&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOrSaleOfEquity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of consideration received by subsidiary or equity investee in exchange for shares of stock issued or sold. Includes amount of cash received, fair value of noncash assets received, and fair value of liabilities assumed by the investor. + References No definition available. + Details
Name: | us-gaap_SaleOfStockConsiderationReceivedPerTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of shares issued during the period as a result of the conversion of convertible securities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29-30) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1E -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495348-112611 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21475-112644 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21463-112644 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of new stock issued during the period. + 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 https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=126973232&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI https://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770 Reference 4: 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(28)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Value of stock issued in lieu of cash for services contributed to the entity. Value of the stock issued includes, but is not limited to, services contributed by vendors and founders. + References No definition available. + Details
Name: | us-gaap_StockIssuedDuringPeriodValueIssuedForServices
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=us-gaap_OverAllotmentOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=syn_FbrCapitalMarketsCoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_WarrantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_SeriesAPreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=us-gaap_PrivatePlacementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_SeriesBPreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |