Note 15 Segment and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Net Revenues	$ 71,186	$ 80,857
Power Semiconductors [Member]
Segment Reporting Information [Line Items]
Net Revenues	51,666	59,582
Integrated Circuits [Member]
Segment Reporting Information [Line Items]
Net Revenues	13,655	15,599
System and RF Power Semiconductors [Member]
Segment Reporting Information [Line Items]
Net Revenues	5,865	5,676
United States [Member]
Segment Reporting Information [Line Items]
Net Revenues	21,558	24,922
France [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,303	1,573
Germany [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	7,653	9,157
Italy [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	973	1,026
Sweden [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,380	1,160
UNITED KINGDOM [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	5,336	7,124
China [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	14,674	13,384
Japan [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,705	1,828
Korea [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,864	2,243
Malaysia [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	703	1,303
Singapore [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	2,593	2,645
India [Member] | Rest Of World [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,348	1,802
Other Geographic Regions [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	7,274	8,064
Other Geographic Regions [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,499	2,579
Other Geographic Regions [Member] | Rest Of World [Member]
Segment Reporting Information [Line Items]
Net Revenues	$ 1,323	$ 2,047