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			10 Months Ended	12 Months Ended			13 Months Ended
	Jan. 07, 2019 shares	Apr. 03, 2018 USD ($) item shares	Apr. 30, 2018 USD ($) shares	Mar. 31, 2018 USD ($) shares	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2018 shares	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($)	Mar. 31, 2019 USD ($)
Licensing and other arrangements
Revenues					$ 375	$ 804
Revenue from contracts with customers					19	500
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
Number of Rezolute's common stock eligible to receive contingent on completion of financing activities \| shares				7,000,000
Number of post-split shares eligible to receive \| shares				140,000
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
Revenues							$ 0
Transaction price		$ 1,800
Transaction price, Shares received (in shares) \| shares		8,093,010
Post-split shares received (in shares) \| shares		161,860
Transaction price, Value of common stock received		$ 1,000
Transaction price, cash consideration		500
Reimbursable technology transfer expense to be received		$ 300
Number of arrangements \| item		1
Upfront consideration to incremental discount for future payment		$ 0
Revenue from contracts with customers										$ 8,500	$ 1,800
Rezolute \| License Agreement
Licensing and other arrangements
Reimbursable technology transfer expense to be received		$ 300
Revenue from contracts with customers					$ 0	$ 0
Rezolute \| Common Stock Purchase Agreement
Licensing and other arrangements
Number of post-split shares eligible to receive \| shares								100,000
Number of Rezolute's shares Company has right and option to sell \| shares	5,000,000			5,000,000						100,000
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%
Transaction price, Shares received (in shares) \| shares			8,093,010
Post-split shares received (in shares) \| shares			161,860
Transaction price, cash consideration			$ 500