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

Subsequent Events - Additional Information (Details)

Subsequent Events - Additional Information (Details) - Servier Loan [Member] € in Millions		1 Months Ended
	Jan. 09, 2015 EUR (€) Tranche	Aug. 31, 2017 EUR (€) Tranche	Jan. 31, 2017 EUR (€)	Jan. 31, 2016 EUR (€)
Subsequent Event [Line Items]
Principal payment amount				€ 3.0
Number of tranches \| Tranche	3
Tranche Two [Member]
Subsequent Event [Line Items]
Maturity date	Jan. 15, 2017
Principal payment amount	€ 5.0
Tranche Three [Member]
Subsequent Event [Line Items]
Maturity date	Jan. 15, 2018
Principal payment amount	€ 7.0
Amendment No.3 [Member] \| Tranche Two [Member]
Subsequent Event [Line Items]
Maturity date			Jul. 15, 2017
Principal payment amount			€ 5.0
Subsequent Event [Member] \| Amendment No.4 [Member] \| Tranche Two [Member]
Subsequent Event [Line Items]
Maturity date		Sep. 15, 2017
Principal payment amount		€ 5.0
Subsequent Event [Member] \| Amendment No.4 [Member] \| Tranche Three [Member]
Subsequent Event [Line Items]
Maturity date		Jan. 15, 2018
Principal payment amount		€ 7.0
Number of tranches \| Tranche		4
Subsequent Event [Member] \| Amendment No.4 [Member] \| Tranche Three in Tranche One [Member]
Subsequent Event [Line Items]
Maturity date		Sep. 30, 2018
Principal payment amount		€ 2.0
Subsequent Event [Member] \| Amendment No.4 [Member] \| Tranche Three in Tranche Two [Member]
Subsequent Event [Line Items]
Maturity date		Sep. 30, 2019
Principal payment amount		€ 2.0
Subsequent Event [Member] \| Amendment No.4 [Member] \| Tranche Three in Tranche Three [Member]
Subsequent Event [Line Items]
Maturity date		Sep. 30, 2020
Principal payment amount		€ 2.0
Subsequent Event [Member] \| Amendment No.4 [Member] \| Tranche Three in Tranche Four [Member]
Subsequent Event [Line Items]
Maturity date		Sep. 30, 2021
Principal payment amount		€ 1.0