XML 69 R49.htm IDEA: XBRL DOCUMENT
v3.22.2.2

STOCKHOLDERS' EQUITY - Equity Financing (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions |  | 2 Months Ended | 3 Months Ended | 6 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Nov. 29, 2021 | Jul. 31, 2021 | Jun. 30, 2021 | Jun. 30, 2021 | Jun. 30, 2022 | Dec. 31, 2021 | Nov. 29, 2019
Class of Stock [Line Items] |  |  |  |  |  |  |
Common stock, par value (in dollars per share) |  |  |  |  | $ 0.001 | $ 0.001 |
ATM Facility |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Common stock, par value (in dollars per share) |  |  |  |  |  |  | $ 0.001
Aggregate sales price |  | $ 200.0 |  |  |  |  |
Shares reserved for future issuance amount |  |  |  |  | $ 97.8 |  |
Commission fixed rate | 3.00% |  |  |  |  |  |
Proceeds from sale of stock |  |  | $ 64.3 | $ 136.8 |  |  |
Sale of stock, number of units issued (in shares) |  |  | 16.5 | 47.1 |  |  |
Weighted-average stock price per share (in dollars per share) |  |  | $ 4.02 | $ 2.99 |  |  |
Issuance of common stock, issuance cost |  |  | $ 2.0 | $ 4.2 |  |  |

X
- Definition Sale Of Stock, Commission Fixed Rate + References No definition available. + Details
Name: | sesn_SaleOfStockCommissionFixedRate
Namespace Prefix: | sesn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Sale Of Stock, Maximum Aggregate Sales Price In Transaction + References No definition available. + Details
Name: | sesn_SaleOfStockMaximumAggregateSalesPriceInTransaction
Namespace Prefix: | sesn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Sale Of Stock, Remaining Shares Amount Available For Future Issuance + References No definition available. + Details
Name: | sesn_SaleOfStockRemainingSharesAmountAvailableForFutureIssuance
Namespace Prefix: | sesn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Sale of Stock, Weighted-Average Price Per Share + References No definition available. + Details
Name: | sesn_SaleOfStockWeightedAveragePricePerShare
Namespace Prefix: | sesn_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Stock Issued During Period, New Issues, Issuance Costs + References No definition available. + Details
Name: | sesn_StockIssuedDuringPeriodNewIssuesIssuanceCosts
Namespace Prefix: | sesn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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 https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Cash received on stock transaction after deduction of issuance costs. + References No definition available. + Details
Name: | us-gaap_SaleOfStockConsiderationReceivedOnTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of shares issued or sold by the subsidiary or equity method investee per stock transaction. + References No definition available. + Details
Name: | us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_CreditFacilityAxis=sesn_ATMFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |