XML 46 R34.htm IDEA: XBRL DOCUMENT
v3.19.1

Common Stock - Additional Information (Detail) | 3 Months Ended | 136 Months Ended
--- | --- | ---
Mar. 31, 2019 Vote | Mar. 31, 2019 USD ($)
Stockholders Equity Note [Abstract] |  |
Number of votes entitled to each share of common stock | Vote | 1 |
Cash dividends | $ |  | $ 0

X
- Definition Number of votes entitled to each share of common stock. + References No definition available. + Details
Name: | sybx_NumberOfVotesEntitledToEachShareOfCommonStock
Namespace Prefix: | sybx_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of paid and unpaid common stock dividends declared with the form of settlement in cash. + 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 http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_DividendsCommonStockCash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_StockholdersEquityNoteAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration