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

Quarterly report pursuant to Section 13 or 15(d)

Long-Term Debt and Other Financings - Servier Loan Agreement - Additional Information (Details)

Long-Term Debt and Other Financings - Servier Loan Agreement - Additional Information (Details)		1 Months Ended			3 Months Ended		6 Months Ended		9 Months Ended		12 Months Ended	44 Months Ended
	Jan. 09, 2015 USD ($) Tranche	Jul. 31, 2015 USD ($)	Jan. 31, 2015 USD ($)	Jan. 31, 2011 USD ($)	Sep. 30, 2015 USD ($) € / $	Sep. 30, 2014 USD ($)	Jul. 31, 2015	Jul. 31, 2011	Sep. 30, 2015 USD ($) € / $	Sep. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) € / $	Jan. 31, 2015	Sep. 30, 2015 EUR (€) € / $	Jan. 09, 2015 EUR (€) Tranche
Debt Instrument [Line Items]
Accrued interest paid									$ 1,452,000	$ 2,848,000
Debt issuance costs											$ 0
Carrying value of the loan					$ 48,585,000				48,585,000
Unrealized foreign exchange gain (loss)									$ 1,344,000	1,541,000
Servier Loan [Member]
Debt Instrument [Line Items]
Date of agreement									Dec. 30, 2010
Maximum borrowing capacity under loan agreement \| €													€ 15,000,000
Proceeds from loan				$ 19,500,000
Interest rate during period								3.22%
Interest rates reset semi-annually, minimum												2.31%
Interest rates reset semi-annually, maximum												3.83%
Accrued interest paid		$ 200,000	$ 200,000
Date of loan amendment									Jan. 09, 2015
Date of agreement, after amendment									Aug. 12, 2013
Number of tranches \| Tranche	3													3
Debt issuance costs	$ 6,000
Unamortized discount on debt	$ 1,900,000				8,900,000				$ 8,900,000
Amortization of debt discount					200,000	$ 500,000			500,000	1,400,000
Carrying value of the loan					15,600,000				15,600,000		16,200,000
Unrealized foreign exchange gain (loss) related to re-measurement of loan discount					17,000	(200,000)			$ (200,000)	(200,000)
Agreement termination date									Sep. 28, 2015
Agreement termination notice period									180 days
Outstanding principal balance					$ 16,900,000				$ 16,900,000		$ 18,200,000
Euro to US Dollar exchange rates \| € / $					1.124				1.124		1.216		1.124
Unrealized foreign exchange gain (loss)					$ (200,000)	$ 1,400,000			$ 1,400,000	$ 1,600,000
Servier Loan [Member] \| Tranche One [Member]
Debt Instrument [Line Items]
Maturity date	Jan. 15, 2016
Principal payment amount \| €														€ 3,000,000
Servier Loan [Member] \| Tranche Two [Member]
Debt Instrument [Line Items]
Maturity date	Jan. 15, 2017
Principal payment amount \| €														5,000,000
Servier Loan [Member] \| Tranche Three [Member]
Debt Instrument [Line Items]
Maturity date	Jan. 15, 2018
Principal payment amount \| €														€ 7,000,000
Servier Loan [Member] \| Mid-January 2015 Through Mid-July 2015 [Member]
Debt Instrument [Line Items]
Interest rate during period							2.16%
Period of interest resetting									6 months
Servier Loan [Member] \| Mid-July 2015 Through Mid-January 2016 [Member]
Debt Instrument [Line Items]
Interest rate during period									2.05%
Period of interest resetting									6 months