XML 88 R68.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Net Income (Loss) per Share Available to Common Stockholders - Outstanding Securities Considered Anti-Dilutive (Details) - shares shares in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |
Antidilutive securities excluded from computation of earnings per share (in shares) | 4,818 | 1,442 | 1,510
Common Stock Options and RSUs [Member] |  |  |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |
Antidilutive securities excluded from computation of earnings per share (in shares) | 346 | 548 | 550
Warrants for Common Stock [Member] |  |  |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |
Antidilutive securities excluded from computation of earnings per share (in shares) | 100 | 894 | 960
Convertible Preferred Stock [Member] |  |  |
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items] |  |  |
Antidilutive securities excluded from computation of earnings per share (in shares) | 4,372 |  |

X
- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
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_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=xoma_CommonStockOptionsAndRestrictedStockUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=us-gaap_WarrantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_ConvertiblePreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |