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

Collaborative, Licensing and Other Arrangements - NIAID - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Oct. 31, 2011	Sep. 30, 2008	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2010	Dec. 31, 2009
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred revenue				$ 1,939
Recognition of revenue			$ 6,383	13,183	$ 24,423
National Institute of Allergy and Infectious Diseases "NIAID" [Member] \| Arrangement with Governmental Agency 2 [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total contract amount awarded		$ 64,800
Increase (decrease) in revenue						$ 900	$ 1,100
Recognition of revenue			200	1,200	4,400
National Institute of Allergy and Infectious Diseases "NIAID" [Member] \| Arrangement with Governmental Agency 3 [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contractual term		3 years
Increase (decrease) in deferred revenue				(1,800)
Deferred revenue				1,900
Remaining deferred revenue				100
National Institute of Allergy and Infectious Diseases "NIAID" [Member] \| Arrangement with Governmental Agency 1 [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Total contract amount awarded	$ 28,000
Contractual term	5 years
Recognition of revenue			$ 4,900	$ 8,400	$ 4,700