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

CONDENSED CONSOLIDATED BALANCE SHEETS (unaudited) (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Stockholders' (deficit) equity:
Common stock, par value (in dollars per share)	$ 0.0075	$ 0.0075
Common stock, shares authorized (in shares)	138,666,666	138,666,666
Common stock, shares outstanding (in shares)	82,887,828	82,447,274

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.