XML 64 R52.htm IDEA: XBRL DOCUMENT
v3.23.3

Stockholders' Equity - Schedule of Common Stock Reserved for Future Issuance (Details) - shares | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Stockholders Equity [Line Items] |  |
Reserved common stock | 16,079,586 | 13,804,406
Common Stock Options Issued and Outstanding |  |
Stockholders Equity [Line Items] |  |
Reserved common stock | 7,920,561 | 7,310,611
Common Stock Awards Issued and Outstanding |  |
Stockholders Equity [Line Items] |  |
Reserved common stock | 5,213,248 | 3,958,478
Remaining Shares Reserved for Issuance under 2018 Equity Incentive Plan and 2021 Equity Inducement Plan |  |
Stockholders Equity [Line Items] |  |
Reserved common stock | 1,903,250 | 1,541,706
Shares Reserved for Issuance Under 2018 Employee Stock Purchase Plan |  |
Stockholders Equity [Line Items] |  |
Reserved common stock | 914,911 | 865,995
Warrants to Purchase Common Stock |  |
Stockholders Equity [Line Items] |  |
Reserved common stock | 127,616 | 127,616

X
- Definition Stockholders equity. + References No definition available. + Details
Name: | stro_StockholdersEquityLineItems
Namespace Prefix: | stro_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

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

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

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

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=stro_TwoThousandEighteenEmployeeStockPurchasePlanMember
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: |