XML 53 R44.htm IDEA: XBRL DOCUMENT
v3.26.1

Common Stock - Summary of Company's Warrants (Details) | 6 Months Ended
--- | ---
Jun. 30, 2026 $ / shares shares
Pre-Funded Warrant |
Class of Warrant or Right [Line Items] |
Number of warrants, Beginning | shares | 0
Number of warrants, Issuance in public offering | shares | 1,179,245
Number of Warrants, Ending | shares | 1,179,245
Weighted-Average Exercise Price Per Share, Beginning | $ / shares | $ 0
Weighted-Average Exercise Price Per Share, Issuance in public offering | $ / shares | 0.00001
Weighted-Average Exercise Price Per Share, Ending | $ / shares | $ 0.00001
Tranche Two Warrant |
Class of Warrant or Right [Line Items] |
Number of warrants, Beginning | shares | 5,769,231
Number of warrants, Issuance in public offering | shares | 0
Number of Warrants, Ending | shares | 5,769,231
Weighted-Average Exercise Price Per Share, Beginning | $ / shares | $ 3.77
Weighted-Average Exercise Price Per Share, Issuance in public offering | $ / shares | 0
Weighted-Average Exercise Price Per Share, Ending | $ / shares | $ 3.77

X
- Definition Exercise price per share or per unit of warrants or rights outstanding, issuance in public offering. + References No definition available. + Details
Name: | ctmx_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRightsIssuanceInPublicOffering
Namespace Prefix: | ctmx_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Issue of shares warrants issuance in public offering. + References No definition available. + Details
Name: | ctmx_IssueOfSharesWarrantsIssuanceInPublicOffering
Namespace Prefix: | ctmx_
Data Type: | xbrli:sharesItemType
Balance Type: | na
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 -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(h)(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-3 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

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_ClassOfWarrantOrRightLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of warrants or rights outstanding. + References No definition available. + Details
Name: | us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=ctmx_PreFundedWarrantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ClassOfWarrantOrRightAxis=ctmx_TrancheTwoWarrantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |