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
	Jan. 09, 2015 USD ($) Tranche	Jan. 31, 2017 USD ($)	Jan. 31, 2016 EUR (€)	Jan. 31, 2011 USD ($)	Mar. 31, 2017 USD ($) € / $	Mar. 31, 2016 USD ($)	Jul. 31, 2017	Jan. 31, 2017 USD ($)	Mar. 31, 2017 EUR (€) € / $	Jan. 31, 2017 EUR (€)	Dec. 31, 2016 USD ($) € / $	Jan. 09, 2015 EUR (€) Tranche
Debt Instrument [Line Items]
Accrued interest paid					$ 396,000	$ 646,000
Carrying value of the loan					$ 26,629,000
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
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					$ 100,000	200,000
Carrying value of the loan					12,544,000						$ 12,231,000
Unrealized foreign exchange gains (loss) related to re-measurement of loan discount					6,000	38,000
Outstanding principal balance					$ 12,800,000						$ 12,600,000
Euro to US Dollar exchange rates \| € / $					1.068				1.068		1.052
Unrealized foreign exchange gains (loss) related to re-measurement of loan					$ (200,000)	$ (500,000)
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 2016 Through Mid-January 2017 [Member]
Debt Instrument [Line Items]
Period of interest resetting								6 months
Interest rate during period								1.81%
Servier Loan [Member] \| Amendment No.3 [Member] \| Tranche Two [Member]
Debt Instrument [Line Items]
Maturity date		Jul. 15, 2017
Principal payment amount \| €										€ 5,000,000
Unamortized discount on debt		$ 400,000						$ 400,000
Servier Loan [Member] \| Forecast [Member] \| Mid-January 2017 Through Mid-July 2017 [Member]
Debt Instrument [Line Items]
Period of interest resetting							6 months
Interest rate during period							1.77%