Document and Entity Information	9 Months Ended
	Dec. 31, 2014	Jan. 23, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	IXYS CORP /DE/
Trading Symbol	IXYS
Entity Central Index Key	0000945699
Document Type	10-Q
Document Period End Date	Dec. 31, 2014
Amendment Flag	false
Current Fiscal Year End Date	--03-31
Entity Well Known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock Shares Outstanding		31,649,158
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3