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

Capital Stock - Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 15, 2021	Jul. 28, 2021	Jul. 15, 2021	May 21, 2021	Apr. 15, 2021	Mar. 17, 2021	Sep. 30, 2021
Dividends
Restricted cash							$ 3,417
8.625% Series A Cumulative, Perpetual Preferred Stock
Dividends
Cash dividend declared (in dollars per share)		$ 0.53906		$ 0.53906		$ 0.71875
Cash dividend paid (in dollars per share)			$ 0.53906		$ 0.71875
Series A Preferred Stock And Series B Preferred Stock
Dividends
Restricted cash							$ 3,400
Depositary Shares
Dividends
Cash dividend declared (in dollars per share)		$ 0.52344		$ 0.55833
Cash dividend paid (in dollars per share)			$ 0.55833
Forecast [Member] \| 8.625% Series A Cumulative, Perpetual Preferred Stock
Dividends
Cash dividend paid (in dollars per share)	$ 0.53906
Forecast [Member] \| Depositary Shares
Dividends
Cash dividend paid (in dollars per share)	$ 0.52344