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

Quarterly report pursuant to Section 13 or 15(d)

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

Long-Term Debt - Servier Loan Agreement - Additional Information (Details)		1 Months Ended		3 Months Ended		6 Months Ended		66 Months Ended
	Jan. 09, 2015 USD ($) Tranche	Jan. 31, 2016 EUR (€)	Jan. 31, 2011 USD ($)	Mar. 31, 2016 USD ($) € / $	Mar. 31, 2015 USD ($)	Jul. 31, 2016	Jul. 31, 2011	Jul. 15, 2016	Mar. 31, 2016 EUR (€) € / $	Dec. 31, 2015 USD ($) € / $	Jan. 09, 2015 EUR (€) Tranche
Debt Instrument [Line Items]
Accrued interest paid				$ 646,000	$ 333,000
Carrying value of the loan				46,251,000						$ 48,667,000
Unrealized foreign exchange gain (loss)				$ (559,000)	1,949,000
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%
Date of loan amendment				Jan. 09, 2015
Date of agreement, after amendment				Aug. 12, 2013
Number of tranches \| Tranche	3										3
Principal payment amount \| €		€ 3,000,000
Accrued interest paid \| €		€ 200,000
Unamortized discount on debt	$ 1,900,000		$ 8,900,000
Amortization of debt discount				$ 200,000	200,000
Carrying value of the loan				12,700,000						15,300,000
Unrealized foreign exchange gains related to re-measurement of loan discount				$ 38,000	200,000
Agreement termination date				Sep. 28, 2015
Agreement termination notice period				180 days
Outstanding principal balance				$ 13,600,000						$ 16,400,000
Euro to US Dollar exchange rates \| € / $				1.136					1.136	1.091
Unrealized foreign exchange gain (loss)				$ (500,000)	$ 1,900,000
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-July 2015 Through Mid-January 2016 [Member]
Debt Instrument [Line Items]
Interest rate during period				2.05%
Period of interest resetting				6 months
Servier Loan [Member] \| Forecast [Member]
Debt Instrument [Line Items]
Interest rates reset semi-annually, minimum								1.95%
Interest rates reset semi-annually, maximum								3.83%
Servier Loan [Member] \| Forecast [Member] \| Mid-January 2016 Through Mid-July 2016 [Member]
Debt Instrument [Line Items]
Interest rate during period						1.95%
Period of interest resetting						6 months