XOMA Corporation Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Cover
- Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- Basis of Presentation and Significant Accounting Policies (Policies)
Notes Tables
Notes Details

Commitments and Contingencies - Additional Information (Details)

v3.10.0.1

Commitments and Contingencies - Additional Information (Details)					3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($) RenewalOption	Jun. 30, 2018 USD ($)	Apr. 14, 2018 USD ($) Facility	Nov. 21, 2017 USD ($) Facility	Sep. 30, 2018 USD ($) RenewalOption	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Sep. 30, 2018 USD ($) RenewalOption
Commitments And Contingencies [Line Items]
Estimate of milestone payments	$ 15,500,000				$ 15,500,000			$ 15,500,000
Operating leases, expiry date								2023-04
Operating leases, number of successive renewal options \| RenewalOption	2				2			2
Operating leases, extended lease term	5 years				5 years			5 years
Operating leases, number of portions of leased facilities \| Facility			1	1
Operating leases, number of leased facilities \| Facility			3	3
Operating leases, sublease commencement date			May 01, 2018	Dec. 26, 2017
Operating leases sublease income receivable			$ 1,100,000	$ 5,100,000
Operating leases sublease expiry date			2023-04	2023-04
Sublease tenant improvement allowance			$ 65,000	$ 800,000
Restructuring Charges [Member]
Commitments And Contingencies [Line Items]
Sublease loss		$ 600,000
Sublease Agreement Commenced on December 26, 2017 [Member]
Commitments And Contingencies [Line Items]
Sublease loss				800,000
Sublease income					$ 400,000			$ 1,100,000
Sublease Agreement Commenced on December 26, 2017 [Member] \| Standby Letter of Credit [Member]
Commitments And Contingencies [Line Items]
Letter of credit amount				$ 1,000,000
Funds drawn from letter of credit	$ 0
Sublease Agreement Commenced on May 1,2018 [Member]
Commitments And Contingencies [Line Items]
Sublease income					$ 100,000			$ 200,000
Sublease broker commissions			$ 89,000
Sublease Agreement Commenced on May 1,2018 [Member] \| Restructuring Charges [Member]
Commitments And Contingencies [Line Items]
Sublease loss						$ 600,000	$ 600,000

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of revenue recognized for the period under subleasing arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 55
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=77891322&loc=d3e41620-112719

+ Details

Name:	us-gaap_OperatingLeasesIncomeStatementSubleaseRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount payable to broker-dealers and clearing organizations, including, but not limited to, securities failed-to-receive, certain deposits received for securities loaned, open transactions, and floor-brokerage payables.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 20
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=35710130&loc=d3e41645-110958

+ Details

Name:	us-gaap_PayablesToBrokerDealersAndClearingOrganizations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of cash outflow for the allowance granted to lessee and/or direct costs incurred by lessor used to prepare the leased premises for tenant's occupancy.

+ References

No definition available.

+ Details

Name:	us-gaap_PaymentsForTenantImprovements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(f))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_ProceedsFromLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Commitments and contingencies.

+ References

No definition available.

+ Details

Name:	xoma_CommitmentsAndContingenciesLineItems
Namespace Prefix:	xoma_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects estimated obligations that are due and payable upon achievement of certain criteria categorized as developmental, regulatory, or commercial milestones.

+ References

No definition available.

+ Details

Name:	xoma_ContractualObligationEstimatedMilestonePayments
Namespace Prefix:	xoma_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee leasing arrangements operating leases expiry month and year.

+ References

No definition available.

+ Details

Name:	xoma_LesseeLeasingArrangementsOperatingLeasesExpiryMonthAndYear
Namespace Prefix:	xoma_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

Operating leases loss on sublease.

+ References

No definition available.

+ Details

Name:	xoma_OperatingLeasesLossOnSublease
Namespace Prefix:	xoma_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Operating leases, number of leased facilities.

+ References

No definition available.

+ Details

Name:	xoma_OperatingLeasesNumberOfLeasedFacilities
Namespace Prefix:	xoma_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Operating leases, number of successive renewal options.

+ References

No definition available.

+ Details

Name:	xoma_OperatingLeasesNumberOfSuccessiveRenewalOptions
Namespace Prefix:	xoma_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	instant

- Definition

Operating leases, sublease commencement date.

+ References

No definition available.

+ Details

Name:	xoma_OperatingLeasesSubleaseCommencementDate
Namespace Prefix:	xoma_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Operating leases sublease expiration date.

+ References

No definition available.

+ Details

Name:	xoma_OperatingLeasesSubleaseExpiryDate
Namespace Prefix:	xoma_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

Operating leases sublease revenue receivable.

+ References

No definition available.

+ Details

Name:	xoma_OperatingLeasesSubleaseRevenueReceivable
Namespace Prefix:	xoma_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Subleased facility number of portions.

+ References

No definition available.

+ Details

Name:	xoma_SubleasedFacilityNumberOfPortions
Namespace Prefix:	xoma_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_RestructuringChargesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=xoma_SubleaseAgreementCommencedOnDecemberTwentySixTwoThousandAndSeventeenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LossContingenciesByNatureOfContingencyAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=xoma_SubleaseAgreementCommencedOnMayOneTwoThousandAndEighteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: