Note 14 Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Net Revenues	$ 63,812	$ 80,041	$ 213,130	$ 280,823
Power Semiconductors [Member]
Segment Reporting Information [Line Items]
Net Revenues	45,011	60,101	152,796	211,296
Integrated Circuits [Member]
Segment Reporting Information [Line Items]
Net Revenues	13,401	13,653	44,100	48,713
System and RF Semiconductors [Member]
Segment Reporting Information [Line Items]
Net Revenues	5,400	6,287	16,234	20,814
United States [Member]
Segment Reporting Information [Line Items]
Net Revenues	19,431	21,751	64,594	77,018
France [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,138	1,936	3,836	5,882
Germany [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	7,433	9,665	24,036	35,969
United Kingdom [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	5,465	6,809	19,018	23,241
China [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	9,699	13,328	33,669	48,864
Japan [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,348	1,817	4,893	6,512
Korea [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,746	2,523	6,071	9,472
Malaysia [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,108	1,262	3,557	3,418
Singapore [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	2,287	2,324	7,441	7,909
Taiwan [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	745	1,550	3,222	5,547
India [Member] | Rest of the World [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,251	1,204	4,523	6,458
Other Geographic Regions [Member] | Europe and Middle East [Member]
Segment Reporting Information [Line Items]
Net Revenues	9,019	12,582	28,496	40,365
Other Geographic Regions [Member] | Asia Pacific [Member]
Segment Reporting Information [Line Items]
Net Revenues	1,490	1,648	4,164	4,734
Other Geographic Regions [Member] | Rest of the World [Member]
Segment Reporting Information [Line Items]
Net Revenues	$ 1,652	$ 1,642	$ 5,610	$ 5,434