Condensed Consolidating Financial Statements (Details) (USD $) In Thousands, unless otherwise specified									12 Months Ended				12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2014 Parent	Mar. 31, 2013 Parent	Mar. 31, 2012 Parent	Mar. 31, 2011 Parent	Mar. 31, 2014 Guarantor Subsidiaries	Mar. 31, 2013 Guarantor Subsidiaries	Mar. 31, 2012 Guarantor Subsidiaries	Mar. 31, 2011 Guarantor Subsidiaries	Mar. 31, 2014 Non-Guarantor Subsidiaries	Mar. 31, 2013 Non-Guarantor Subsidiaries	Mar. 31, 2012 Non-Guarantor Subsidiaries	Mar. 31, 2011 Non-Guarantor Subsidiaries	Mar. 31, 2014 Reclassifications and Eliminations	Mar. 31, 2013 Reclassifications and Eliminations	Mar. 31, 2014 10.5% Senior Notes	Mar. 31, 2013 10.5% Senior Notes	May 05, 2010 10.5% Senior Notes
Condensed Financial Statements, Captions [Line Items]
Interest rate of senior notes (as a percent)																			10.50%	10.50%	10.50%
Percentage of ownership interest									100.00%
Percentage of capital stock													51.00%
Current assets:
Cash and cash equivalents	$ 57,929	$ 95,978	$ 210,521	$ 152,051	$ 616	$ 17,202	$ 7,933	$ 6,417	$ 22,200	$ 52,056	$ 178,205	$ 119,326	$ 35,113	$ 26,720	$ 24,383	$ 26,308
Accounts receivable, net	98,947	93,774							49,462	42,051			49,485	51,723
Intercompany receivable					318,582	287,513			329,211	251,524			203,018	150,376			(850,811)	(689,413)
Inventories, net	187,974	198,888							119,340	126,286			68,634	72,602
Prepaid expenses and other	36,871	41,101			3,146	3,186			15,286	13,564			21,380	27,303			(2,941)	(2,952)
Deferred income taxes	6,695	4,167							1,022	578			5,673	3,589
Current assets of discontinued operations	12,160	9,517											12,160	9,517
Total current assets	400,576	443,425			322,344	307,901			536,521	486,059			395,463	341,830			(853,752)	(692,365)
Property and equipment, net	292,648	303,682			329	361			104,874	111,584			187,445	191,737
Investment in NEC TOKIN	46,419	52,738							46,419	52,738
Investments in subsidiaries					402,090	423,695			424,386	424,386			30,285	10,750			(856,761)	(858,831)
Goodwill	35,584	35,584	36,676						35,584	35,584
Intangible assets, net	37,184	38,646							28,380	29,763			8,804	8,883
Restricted cash	13,512	17,397							13,512	17,397
Deferred income taxes	6,778	7,994							1,010	1,500			5,768	6,494
Other assets	10,130	10,149			5,415	6,741			3,895	3,173			820	235
Noncurrent assets of discontinued operations	836	1,976											836	1,976
Long-term intercompany receivable					81,746	75,919			60,663	56,338			2,801	2,800			(145,210)	(135,057)
Total assets	843,667	911,591			811,924	814,617			1,255,244	1,218,522			632,222	564,705			(1,855,723)	(1,686,253)
Current liabilities:
Current portion of long-term debt	7,297	10,793			5,988	9,561				16			1,309	1,216
Accounts payable, trade	74,818	70,774			84	61			36,579	37,444			38,155	33,269
Intercompany payable					176,624	100,947			570,535	481,707			103,652	106,759			(850,811)	(689,413)
Accrued expenses	76,468	93,178			34,236	37,490			13,698	19,615			28,534	36,073
Income taxes payable	980	1,074							2,909	3,046			1,012	980			(2,941)	(2,952)
Current liabilities of discontinued operations	7,269	5,661											7,269	5,661
Total current liabilities	166,832	181,480			216,932	148,059			623,721	541,828			179,931	183,958			(853,752)	(692,365)
Long-term debt, less current portion	391,292	372,707			372,251	372,157			6,449				12,592	550
Other non-current obligations	55,864	69,022			857	17,485			3,311	3,899			51,696	47,638
Deferred income taxes	5,203	8,542							3,258	2,808			1,945	5,734
Noncurrent liabilities of discontinued operations	2,592	2,924											2,592	2,924
Long-term intercompany payable									81,747	75,919			63,463	59,138			(145,210)	(135,057)
Stockholders' equity	221,884	276,916	358,996	359,753	221,884	276,916			536,758	594,068			320,003	264,763			(856,761)	(858,831)
Total liabilities and stockholders' equity	$ 843,667	$ 911,591			$ 811,924	$ 814,617			$ 1,255,244	$ 1,218,522			$ 632,222	$ 564,705			$ (1,855,723)	$ (1,686,253)