Note 2 Summary of Significant Accounting Policies (Narratives) (Details)	12 Months Ended																12 Months Ended		1 Months Ended		12 Months Ended
	Mar. 31, 2015 USD ($) N	Mar. 31, 2014 USD ($) N	Mar. 31, 2013 USD ($) N	Mar. 31, 2015 Distributor 1 [Member]	Mar. 31, 2013 Distributor 1 [Member]	Mar. 31, 2015 Distributor 2 [Member]	Mar. 31, 2014 Distributor 2 [Member]	Mar. 31, 2013 Distributor 2 [Member]	Mar. 31, 2015 Powersem GmbH [Member] USD ($)	Mar. 31, 2014 Powersem GmbH [Member] USD ($)	Mar. 31, 2013 Powersem GmbH [Member] USD ($)	Mar. 31, 2015 EB Tech Ltd [Member] USD ($)	Mar. 31, 2014 EB Tech Ltd [Member] USD ($)	Mar. 31, 2013 EB Tech Ltd [Member] USD ($)	Mar. 31, 2015 ATEC [Member] USD ($)	Dec. 12, 2014 ATEC [Member]	Mar. 31, 2015 June 2005 IKB Deutshe Industriebank Loans Payable [Member] USD ($)	Mar. 31, 2015 June 2005 IKB Deutshe Industriebank Loans Payable [Member] EUR (€)	Apr. 30, 2015 April 2015 IKB Deutshe Industriebank Loan Payable [Member] USD ($)	Apr. 30, 2015 April 2015 IKB Deutshe Industriebank Loan Payable [Member] EUR (€)	Mar. 31, 2015 Equipment Owned [Member]	Mar. 31, 2015 Property and Plant [Member]
Revenue Recognition [Abstract]
Revenue from Distributors	55.60%
Sales Returns under Stock Rotation	$ 1,700,000	$ 1,500,000	$ 2,400,000
Restricted Cash and Investments, Current [Abstract]
Restricted Cash and Cash Equivalents, Current	266,000	337,000
Inventory Disclosure [Abstract]
Gross Profit Margin from Sales of Excess Inventory	100.00%
Product Part Numbers	more than 10,000
Inventory Valuation Reserves, Lower of Cost or Market Value	444,000	474,000
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Estimated Useful Lives																					1 to 14 years	24 years to 50 years
Property, Plant and Equipment, Depreciation Methods	straight-line
Debt Instrument [Line Items]
Debt Instrument, Issuance Date																	Jun. 10, 2005	Jun. 10, 2005	Apr. 01, 2015	Apr. 01, 2015
Debt Instrument, Face Amount																	12,200,000	10,000,000	7,200,000	6,500,000
Debt Instrument, Maturity Date																	Jun. 30, 2020	Jun. 30, 2020	Mar. 31, 2022	Mar. 31, 2022
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage									45.00%			20.00%			24.30%	24.30%
Income (Loss) from Equity Method Investments									7,000	115,000	107,000	126,000	188,000	124,000	(140,000)
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Method	straight-line method or accelerated method
Marketing and Advertising Expense [Abstract]
Advertising Expense	$ 437,000	$ 631,000	$ 649,000
Risks and Uncertainties [Abstract]
Percentage of Wafers Manufactured Internally	54.00%
Percentage of Wafers Manufactured Externally	46.00%
Concentration Risk, Labor Subject to Collective Bargaining Arrangements	Employees Covered by Collective Bargaining Arrangements Approximately 50.6% and 94.4% of our employees in the United Kingdom and Germany, respectively, are covered by collective bargaining arrangements.
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage				10.50%	13.20%	10.20%	10.80%	10.30%
Number Of Entity Wide Revenue Major Customers	2	1	2