Note 14 Segment Information (Narratives) (Details)	3 Months Ended
Jun. 30, 2012 N	Jun. 30, 2011 N
Segment Reporting [Abstract]
Top Customer Percentage More Than 10% of Total Revenue	12.40%	12.80%
Second Customer Percentage More Than 10% of Total Revenue	11.70%	11.00%
Number of Major Customers	2	2

Percentage of revenue generated from the second ranked external customer that accounts for 10 percent or more of an entity's revenues.

No definition available.

Name:	ixys_EntityWideRevenueSecondCustomerPercentage
Namespace Prefix:	ixys_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration