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

Royalty Purchase Agreements - Aronora (Details)

Royalty Purchase Agreements - Aronora (Details) $ in Thousands		1 Months Ended	12 Months Ended
	Apr. 07, 2019 USD ($) item	Sep. 30, 2019 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Agreements
Long-term royalty receivables			$ 34,575	$ 34,375	$ 15,000
Contingent consideration under royalty purchase agreements			75	75
Impairment of long-term royalty receivable			0	0
Payments to acquire milestones and royalties			1,200	19,300
Proceeds from issuance of long-term debt				$ 9,500
Aronora \| Non-Bayer Products
Agreements
Number of drug candidates \| item	2
Aronora \| Royalty Purchase Agreement
Agreements
Number of drug candidates \| item	5
Non-royalties to be received (as a percent)	10.00%
Future non-royalty payments to be received (as a percent)	5.00%
Multiplier for cumulative amount of consideration paid \| item	2
Upfront payment	$ 6,000
Threshold amount of cumulative royalties on net sales per product	250,000
Long-term royalty receivables	9,000
Contingent consideration under royalty purchase agreements	3,000		0
Payments of contingent consideration		$ 3,000
Impairment of long-term royalty receivable			$ 0
Aggregate milestones payments per product	85,000
Aronora \| Royalty Purchase Agreement \| Silicon Valley Bank Loans
Agreements
Upfront payment	$ 3,000
Aronora \| Royalty Purchase Agreement \| Bayer Products
Agreements
Number of drug candidates \| item	3
Number of drug candidates subject to exclusive license option \| item	1
Royalties on net sales (as a percent)	100.00%
Non-royalties to be received (as a percent)	10.00%
Contingent future cash payment for each product	$ 1,000
Potential future cash payments	$ 3,000
Aronora \| Royalty Purchase Agreement \| Non-Bayer Products
Agreements
Non-royalties to be received (as a percent)	10.00%