Note 15 Segment and Geographic Information (Tables)

12 Months Ended

Mar. 31, 2014

Segment Reporting [Abstract]

Schedule of Revenue from External Customers by Geographic Area [Table Text Block]

		Year Ended March 31,
		2014		2013		2012
United States		$	89,734	$	84,789	$	103,122
Europe and the Middle East
	France		5,554		5,235		7,433
	Germany		34,423		32,287		47,499
	Italy		4,506		4,087		6,274
	Sweden		4,938		4,588		5,297
	Switzerland		3,714		3,216		4,606
	United Kingdom		19,524		23,853		31,131
	Other		26,390		25,302		36,321
Asia Pacific
	China		83,849		44,504		61,723
	Japan		6,740		6,514		9,070
	Korea		19,466		8,311		11,988
	Malaysia		3,766		4,606		4,744
	Singapore		11,838		9,994		10,332
	Taiwan		2,962		3,981		6,797
	Thailand		3,031		2,529		2,587
	Other		3,989		2,965		3,896
Rest of the World
	India		5,245		6,080		8,198
	Other		6,661		7,173		6,986
Total		$	336,330	$	280,014	$	368,004

Revenue from External Customers by Products and Services [Table Text Block]

	Year Ended March 31,
	2014		2013			2012
Power semiconductors	$	222,813	$	200,907	$	277,718
Integrated circuits		91,189		57,993		63,597
Systems and RF power semiconductors		22,328		21,114		26,689
Total	$	336,330	$	280,014	$	368,004

Schedule of Revenue from External Customers and Long-lived Assets, by Geographical Areas [Table Text Block]

		Year Ended March 31,
		2014		2013		2012
Net revenues:
	Foreign	$	167,428	$	134,962	$	175,667
	Domestic		168,902		145,052		192,337
		$	336,330	$	280,014	$	368,004
Net income:
	Foreign	$	4,087	$	7,774	$	22,487
	Domestic		1,959		(126)		7,819
		$	6,046	$	7,648	$	30,306
				Year Ended March 31,
				2014		2013
Property, plant and equipment, net:
	United States			$	27,287	$	29,308
	Germany				21,697		20,711
	United Kingdom				1,579		1,971
	Other countries				6		5
	Total property, plant and equipment			$	50,569	$	51,995