XML 88 R76.htm IDEA: XBRL DOCUMENT
v3.22.4

INCOME TAXES - Schedule of Credit Carryforwards (Details) $ in Millions | Dec. 31, 2022 USD ($)
--- | ---
United States: | Federal |
Income Taxes [Line Items] |
NOL carryforwards | $ 117.7
United States: | State |
Income Taxes [Line Items] |
NOL carryforwards | 138.4
Indefinite | United States: | Federal |
Income Taxes [Line Items] |
NOL carryforwards | 101.2
R&D credit carryforwards | United States: | Federal |
Income Taxes [Line Items] |
Tax credit carryforwards | 2.6
R&D credit carryforwards | United States: | State |
Income Taxes [Line Items] |
Tax credit carryforwards | 0.9
R&D credit carryforwards | Canada |
Income Taxes [Line Items] |
Tax credit carryforwards | 5.1
Non-capital loss carryforwards | Canada |
Income Taxes [Line Items] |
Tax credit carryforwards | 43.2
Investment tax credit carryforwards | Canada |
Income Taxes [Line Items] |
Tax credit carryforwards | $ 1.2

X
- Definition Income Taxes [Line Items] + References No definition available. + Details
Name: | sesn_IncomeTaxesLineItems
Namespace Prefix: | sesn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32559-109319 + Details
Name: | us-gaap_OperatingLossCarryforwards
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=121826272&loc=d3e32559-109319 + Details
Name: | us-gaap_TaxCreditCarryforwardAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_StatementGeographicalAxis=country_US
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_DomesticCountryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | sesn_NetOperatingLossCarryforwardAxis=sesn_IndefiniteMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=us-gaap_ResearchMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=country_CA
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=sesn_NonCapitalLossCarryforwardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TaxCreditCarryforwardAxis=us-gaap_InvestmentCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |