XOMA Corporation Annual report pursuant to Section 13 and 15(d)

Lease Agreements - Sublease Agreements (Details)

Lease Agreements - Sublease Agreements (Details) $ in Thousands					1 Months Ended	3 Months Ended	12 Months Ended				36 Months Ended
	Dec. 18, 2019 USD ($) item	Oct. 24, 2018 facility	May 01, 2018 USD ($) facility	Dec. 26, 2017 USD ($) facility	Jan. 31, 2019 USD ($) facility	Jun. 30, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 17, 2019 facility	Dec. 31, 2018 USD ($)	Dec. 31, 2016 facility	Dec. 31, 2019 item
Leased facilities, Berkeley, California
Leases
Number of operating leases terminated early \| item	2
Lease termination loss	$ 400						$ 400
Operating leases, number of subtenants \| item											4
Operating leases, number of leased facilities \| facility		3	3	3	3			2		2
Sublease loss						$ 600
Portion of leased facilities, Berkeley, California, subleased December 26, 2017
Leases
Number of facilities for which a portion was subleased \| facility				1
Subtenant improvement allowance provided to subtenant				$ 800
Amount of security provided by sub-lessee				$ 1,000
Sublease income, 2019							1,400
Sublease income, 2018									$ 1,500
Portion of leased facilities, Berkeley, California, subleased May 1, 2018
Leases
Number of facilities for which a portion was subleased \| facility			1
Subtenant improvement allowance provided to subtenant			$ 65
Sublease broker commissions			89
Sublease loss			$ 600
Sublease income, 2019							400
Sublease income, 2018									300
Portion of leased facilities, Berkeley, California, subleased October 24, 2018
Leases
Number of facilities for which a portion was subleased \| facility		1
Sublease income, 2019							600
Sublease income, 2018									$ 100
Portion of leased facilities, Berkeley, California, subleased January 18, 2019
Leases
Number of facilities for which a portion was subleased \| facility					1
Subtenant improvement allowance provided to subtenant					$ 91
Sublease broker commissions					$ 53
Sublease income, 2019							$ 600