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

Quarterly report pursuant to Section 13 or 15(d)

Licensing and Other Arrangements - Rezolute - First Amendment (Details)

Licensing and Other Arrangements - Rezolute - First Amendment (Details) $ in Thousands					1 Months Ended			3 Months Ended				12 Months Ended			13 Months Ended
	Jan. 30, 2019 USD ($)	Jan. 07, 2019 USD ($)	Apr. 03, 2018 USD ($) item shares	Dec. 06, 2017 shares	Mar. 31, 2019 USD ($)	Apr. 30, 2018 USD ($) shares	Mar. 31, 2018 USD ($) shares	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2019 shares	Dec. 31, 2018 USD ($)	Mar. 31, 2019 USD ($)
Licensing and other arrangements
Revenues								$ 804		$ 8,131
Revenue from contracts with customers								500		$ 8,026
Rezolute
Licensing and other arrangements
Revenues											$ 0
Rezolute \| License Agreement and Common Stock Purchase Agreement
Licensing and other arrangements
Amount of cash eligible to receive							$ 6,000
Amount of Rezolute's common stock eligible to receive		$ 8,500					$ 8,500
Number of Rezolute's common stock eligible to receive contingent on completion of financing activities \| shares							7,000,000
Gross proceeds to be raised for qualified financing															$ 20,000
Additional common stock to be received if Rezolute did not complete financing															$ 8,500
Common stock trading period															10 days
Eligible to receive, in order to maintain license agreement												$ 15,000
Transaction price, Shares received (in shares) \| shares			8,093,010			8,093,010
Transaction price, cash consideration			$ 500			$ 500
Number of arrangements \| item			1
Transaction price			$ 1,800
Transaction price, Value of common stock received			1,000
Reimbursable technology transfer expense received	$ 300		300
Upfront consideration to incremental discount for future payment			0
Revenue from contracts with customers					$ 2,500				$ 6,000					$ 1,800
Rezolute \| License Agreement
Licensing and other arrangements
Reimbursable technology transfer expense received			$ 300
Revenue from contracts with customers								$ 0
Rezolute \| Common Stock Purchase Agreement
Licensing and other arrangements
Number of Rezolute's shares Company has right and option to sell if Rezolute does not list common stock shares on national exchange \| shares				5,000,000									5,000,000
Percent of Rezolute's shares held Company has right and option to sell if Rezolute does not list common stock shares on national exchange				33.33%