Note 14 Segment and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Net Revenues	$ 88,080	$ 71,186
Power Semiconductors [Member]
Segment Reporting Information [Line Items]
Net Revenues	57,968	51,666
Integrated Circuits [Member]
Segment Reporting Information [Line Items]
Net Revenues	23,882	13,655
System and RF Power Semiconductors [Member]
Segment Reporting Information [Line Items]
Net Revenues	6,230	5,865
United States [Member]
Segment Reporting Information [Line Items]
Net Revenues	22,504	21,558
France [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,852	1,303
Germany [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	8,449	7,653
Italy [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,473	973
Sweden [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,285	1,380
Switzerland [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	818	1,037
United Kingdom [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	5,379	5,336
China [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	20,402	14,674
Japan [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,801	1,705
Korea [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	6,439	1,864
Malaysia [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,632	703
Singapore [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	3,157	2,593
India [Member] | Rest Of World [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,249	1,348
Other Geographic Regions [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	6,969	6,237
Other Geographic Regions [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	3,158	1,499
Other Geographic Regions [Member] | Rest Of World [Member]
Segment Reporting Information [Line Items]
Net Revenues	$ 1,513	$ 1,323