Condensed Consolidating Financial Statements - Balance Sheet (Details) - USD ($) $ in Thousands		12 Months Ended
	May. 05, 2010	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Current assets:
Cash and cash equivalents		$ 65,004	$ 56,362	$ 57,929	$ 95,978
Accounts receivable, net		93,168	90,857
Intercompany receivable		0	0
Inventories, net		168,879	171,843
Prepaid expenses and other		25,496	41,503
Deferred income taxes			0
Total current assets		352,547	360,565
Property and equipment, net		241,839	249,641
Investment in NEC TOKIN		20,334	45,016
Investments in subsidiaries		0	0
Goodwill		40,294	35,584
Intangible assets, net		33,301	33,282
Restricted cash			0
Deferred income taxes		8,397	9,774
Other assets		5,832	12,831
Long-term intercompany receivable		0	0
Total assets		702,544	746,693
Current liabilities:
Current portion of long-term debt		2,000	962
Accounts payable, trade		70,981	69,785
Intercompany payable		0	0
Accrued expenses		50,320	60,456
Income taxes payable		453	884
Total current liabilities		123,754	132,087
Long-term debt, less current portion		388,597	390,409
Other non-current obligations		74,892	57,131
Deferred income taxes		2,820	2,384
Long-term intercompany payable		0	0
Stockholders' equity		112,481	164,682	221,884	276,916
Total liabilities and stockholders' equity		702,544	746,693
Parent
Current assets:
Cash and cash equivalents		640	640	616	17,202
Accounts receivable, net		0	0
Intercompany receivable		30,210	321,233
Inventories, net		0	0
Prepaid expenses and other		3,325	3,191
Total current assets		34,175	325,064
Property and equipment, net		255	293
Investment in NEC TOKIN		0	0
Investments in subsidiaries		382,108	401,062
Goodwill		0	0
Intangible assets, net		0	0
Restricted cash			0
Deferred income taxes		0	0
Other assets		2,764	4,088
Long-term intercompany receivable		67,500	63,788
Total assets		486,802	794,295
Current liabilities:
Current portion of long-term debt		2,000	0
Accounts payable, trade		20	47
Intercompany payable		280	254,852
Accrued expenses		17,305	17,253
Income taxes payable		0	0
Total current liabilities		19,605	272,152
Long-term debt, less current portion		354,716	357,461
Other non-current obligations		0	0
Deferred income taxes		0	0
Long-term intercompany payable		0	0
Stockholders' equity		112,481	164,682
Total liabilities and stockholders' equity		$ 486,802	794,295
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Percentage of ownership interest		100.00%
Current assets:
Cash and cash equivalents		$ 36,209	33,094	22,200	52,056
Accounts receivable, net		41,025	35,535
Intercompany receivable		132,523	403,557
Inventories, net		113,289	119,221
Prepaid expenses and other		12,161	21,134
Total current assets		335,207	612,541
Property and equipment, net		93,936	100,844
Investment in NEC TOKIN		20,334	45,016
Investments in subsidiaries		429,723	423,737
Goodwill		40,294	35,584
Intangible assets, net		27,252	26,998
Restricted cash			0
Deferred income taxes		800	971
Other assets		2,452	7,824
Long-term intercompany receivable		41,428	39,151
Total assets		991,426	1,292,666
Current liabilities:
Current portion of long-term debt		0	500
Accounts payable, trade		34,618	36,565
Intercompany payable		275,498	578,318
Accrued expenses		11,807	16,644
Income taxes payable		2,983	2,928
Total current liabilities		324,906	634,955
Long-term debt, less current portion		19,881	20,948
Other non-current obligations		25,797	2,987
Deferred income taxes		2,242	2,241
Long-term intercompany payable		67,500	63,789
Stockholders' equity		551,100	567,746
Total liabilities and stockholders' equity		991,426	1,292,666
Non-Guarantor Subsidiaries
Current assets:
Cash and cash equivalents		28,155	22,628	35,113	26,720
Accounts receivable, net		52,143	55,322
Intercompany receivable		170,224	195,518
Inventories, net		55,590	52,622
Prepaid expenses and other		12,974	20,164
Total current assets		319,086	346,254
Property and equipment, net		147,648	148,504
Investment in NEC TOKIN		0	0
Investments in subsidiaries		93,359	93,359
Goodwill		0	0
Intangible assets, net		6,049	6,284
Restricted cash			0
Deferred income taxes		7,597	8,803
Other assets		616	919
Long-term intercompany receivable		1,088	1,088
Total assets		575,443	605,211
Current liabilities:
Current portion of long-term debt		0	462
Accounts payable, trade		36,343	33,173
Intercompany payable		57,179	87,138
Accrued expenses		21,208	26,559
Income taxes payable		434	942
Total current liabilities		115,164	148,274
Long-term debt, less current portion		14,000	12,000
Other non-current obligations		49,095	54,144
Deferred income taxes		578	143
Long-term intercompany payable		42,516	40,238
Stockholders' equity		354,090	350,412
Total liabilities and stockholders' equity		575,443	605,211
Reclassifications and Eliminations
Current assets:
Cash and cash equivalents		0	0	$ 0	$ 0
Accounts receivable, net		0	0
Intercompany receivable		(332,957)	(920,308)
Inventories, net		0	0
Prepaid expenses and other		(2,964)	(2,986)
Total current assets		(335,921)	(923,294)
Property and equipment, net		0	0
Investment in NEC TOKIN		0	0
Investments in subsidiaries		(905,190)	(918,158)
Goodwill		0	0
Intangible assets, net		0	0
Restricted cash			0
Deferred income taxes		0	0
Other assets		0	0
Long-term intercompany receivable		(110,016)	(104,027)
Total assets		(1,351,127)	(1,945,479)
Current liabilities:
Current portion of long-term debt		0	0
Accounts payable, trade		0	0
Intercompany payable		(332,957)	(920,308)
Accrued expenses		0	0
Income taxes payable		(2,964)	(2,986)
Total current liabilities		(335,921)	(923,294)
Long-term debt, less current portion		0	0
Other non-current obligations		0	0
Deferred income taxes		0	0
Long-term intercompany payable		(110,016)	(104,027)
Stockholders' equity		(905,190)	(918,158)
Total liabilities and stockholders' equity		$ (1,351,127)	$ (1,945,479)
10.5% Senior Notes
Condensed Financial Statements, Captions [Line Items]
Stated interest rate (as a percent)	10.50%	10.50%
Percentage of capital stock	51.00%
10.5% Senior Notes | Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Percentage of capital stock	51.00%