XML 93 R73.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Capital Stock - Summary of Common Stock Warrants Outstanding (Details) - $ / shares | 1 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | ---
Feb. 29, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Mar. 31, 2012
Class Of Warrant Or Right [Line Items] |  |  |  |
Expiration Date | 2021-02 |  |  |
Exercise price of warrants (in dollars per share) | $ 15.40 |  |  |
Number of Shares |  | 17,312 | 498,556 |
Five Year Warrants Issued in March 2012 [Member] |  |  |  |
Class Of Warrant Or Right [Line Items] |  |  |  |
Exercise price of warrants (in dollars per share) |  |  |  | $ 35.20
Five Year Warrants Issued in March 2012 [Member] | Contingent Warrant Liability [Member] |  |  |  |
Class Of Warrant Or Right [Line Items] |  |  |  |
Issuance Date |  | 2012-03 |  |
Expiration Date |  | 2017-03 |  |
Exercise price of warrants (in dollars per share) |  | $ 35.20 |  |
Number of Shares |  |  | 479,277 |
Five Year Warrants Issued in September 2012 [Member] | Stockholders' Equity (Deficit) [Member] |  |  |  |
Class Of Warrant Or Right [Line Items] |  |  |  |
Issuance Date |  | 2012-09 |  |
Expiration Date |  | 2017-09 |  |
Exercise price of warrants (in dollars per share) |  | $ 70.80 |  |
Number of Shares |  |  | 1,967 |
Five Year Warrants Issued in February 2015 [Member] | Stockholders' Equity (Deficit) [Member] |  |  |  |
Class Of Warrant Or Right [Line Items] |  |  |  |
Issuance Date |  | 2015-02 |  |
Expiration Date |  | 2020-02 |  |
Exercise price of warrants (in dollars per share) |  | $ 66.20 |  |
Number of Shares |  | 9,063 | 9,063 |
Five Year Warrants Issued in February 2016 [Member] | Stockholders' Equity (Deficit) [Member] |  |  |  |
Class Of Warrant Or Right [Line Items] |  |  |  |
Issuance Date |  | 2016-02 |  |
Expiration Date |  | 2021-02 |  |
Exercise price of warrants (in dollars per share) |  | $ 15.40 |  |
Number of Shares |  | 8,249 | 8,249 |

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
Namespace Prefix: | us-gaap_
Data Type: | num: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 Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
Name: | us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Common stock warrants expiration date. + References No definition available. + Details
Name: | xoma_CommonStockWarrantsExpirationDate
Namespace Prefix: | xoma_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Issuance date of common stock warrants. + References No definition available. + Details
Name: | xoma_IssuanceDateOfCommonStockWarrants
Namespace Prefix: | xoma_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_FairValueByLiabilityClassAxis=xoma_ContingentWarrantLiabilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_FairValueByLiabilityClassAxis=xoma_StockholdersEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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