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

Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies - Additional Information (Details)

Commitments and Contingencies - Additional Information (Details)				1 Months Ended		3 Months Ended
	Mar. 31, 2019 USD ($) Facility Subtenant Lease	Apr. 14, 2018 USD ($) Facility	Nov. 21, 2017 USD ($) Facility	Jan. 31, 2019 USD ($) Facility	Oct. 31, 2018 USD ($) Facility	Mar. 31, 2019 USD ($) Facility Subtenant Lease	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2016 Facility
Commitments And Contingencies [Line Items]
Estimate of milestone payments	$ 7,600,000					$ 7,600,000
Operating leases, number of leased facilities \| Facility		3	3	3	3
Number of operating leases right of use assets and lease liability recognized \| Lease	3					3
Rent expense recognized for operating leases						$ 600,000
Variable lease payments						600,000
Operating leases, number of portions of leased facilities \| Facility		1	1	1	1
Operating leases, sublease commencement date		May 01, 2018	Dec. 26, 2017	Jan. 18, 2019	Oct. 24, 2018
Operating leases sublease income plus reimbursement of operating expenses receivable		$ 1,100,000	$ 5,100,000
Operating leases sublease expiry date		2023-04	2023-04	2023-04	2021-05
Sublease tenant improvement allowance		$ 65,000	$ 800,000	$ 91,000,000
Operating leases sublease income receivable				1,700,000	$ 1,700,000
Sublease Agreement Commenced on December 26, 2017 [Member]
Commitments And Contingencies [Line Items]
Sublease loss			800,000
Sublease income						400,000		$ 400,000
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
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
Sublease Agreement Commenced on October 24,2018 [Member]
Commitments And Contingencies [Line Items]
Sublease income						200,000
Sublease broker commissions					$ 137,000
Sublease Agreement Commenced on January 18, 2019 [Member]
Commitments And Contingencies [Line Items]
Sublease income						$ 100,000
Sublease broker commissions				$ 53,000
Berkeley, California [Member]
Commitments And Contingencies [Line Items]
Operating leases, number of leased facilities \| Facility	2					2			2
Operating leases, number of subtenants \| Subtenant	4					4
Emeryville, California [Member]
Commitments And Contingencies [Line Items]
Operating leases, number of leased facilities \| Facility	1					1
Operating leases, description						The Emeryville lease contains both an option to early terminate the lease and an option to extend the lease for an additional term, however, the Company is not reasonably assured to exercise either option.
Operating leases, option to extend, description						option to extend the lease
Operating leases, option to extend						true
Operating leases, option to terminate, description						option to early terminate the lease
Operating leases, option to terminate						true
Operating leases, expiry date						2023-02
Maximum [Member] \| Berkeley, California [Member]
Commitments And Contingencies [Line Items]
Operating leases, remaining lease term						4 years
Minimum [Member] \| Berkeley, California [Member]
Commitments And Contingencies [Line Items]
Operating leases, remaining lease term						2 years
Royalty Purchase Agreement [Member] \| Bioasis Technologies Inc [Member]
Commitments And Contingencies [Line Items]
Estimated fair value of contingent consideration	$ 100,000					$ 100,000
Royalty Purchase Agreement [Member] \| Bioasis Technologies Inc [Member] \| Maximum [Member]
Commitments And Contingencies [Line Items]
Contingent consideration liability	$ 200,000					$ 200,000