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Stock Based Compensation - ESPP (Details) | 9 Months Ended
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Sep. 30, 2022
2015 ESPP |
Share-based compensation |
Percentage of compensation of eligible employees to purchase shares of entity common stock at discount through payroll deductions | 85.00%

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- 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
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Period Type: | duration

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- Definition Refers the percentage of compensation deduction in eligible employees salary to purchase entity common stock. + References No definition available. + Details
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Namespace Prefix: | xoma_
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Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |