XML 84 R78.htm IDEA: XBRL DOCUMENT
v3.20.1

Subsequent Event (Details) | Apr. 15, 2020 | Feb. 29, 2020 | Dec. 31, 2019
--- | --- | --- | ---
BVF | Xoma Corporation | Common Stock |  |  |
Subsequent Event |  |  |
Ownership percentage on outstanding shares |  |  | 27.10%
BVF | Series Y Preferred Stock |  |  |
Subsequent Event |  |  |
Beneficial ownership limitation (as a percent) |  | 50.00% |
Subsequent Event | BVF | Xoma Corporation | Common Stock |  |  |
Subsequent Event |  |  |
Ownership percentage on outstanding shares | 36.60% |  |

X
- Definition The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the beneficial ownership limitation. + References No definition available. + Details
Name: | xoma_BeneficialOwnershipLimitation
Namespace Prefix: | xoma_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=xoma_BiotechnologyValueFundLPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=xoma_XomaCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | srt_CounterpartyNameAxis=xoma_BiotechnologyValueFundLPMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |