Document and Entity Information	9 Months Ended
	Dec. 31, 2011	Jan. 26, 2012
Document And Entity Information [Abstract]
Entity Registrant Name	IXYS CORP /DE/
Entity Central Index Key	0000945699
Document Type	10-Q
Document Period End Date	Dec. 31, 2011
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		31,253,875
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	Q3