Condensed Consolidating Financial Statements - Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Net sales	$ 183,926	$ 177,184	$ 186,123	$ 187,590	$ 193,708	$ 201,310	$ 215,293	$ 212,881	$ 734,823	$ 823,192	$ 833,666
Operating costs and expenses:
Cost of sales									571,543	663,683	712,925
Selling, general and administrative expenses									101,446	98,533	95,856
Research and development									24,955	25,802	24,466
Restructuring charges									4,178	13,017	14,122
Write down of long-lived assets									0	0	4,476
Net (gain) loss on sales and disposals of assets									375	(221)	32
Gain (Loss) On Inter-company Asset Transfer											0
Total operating costs and expenses									702,497	800,814	851,877
Operating income (loss)	8,603	8,493	13,987	1,243	912	9,302	12,770	(606)	32,326	22,378	(18,211)
Interest income									(14)	(15)	(195)
Interest expense									39,605	40,701	40,962
Change in value of NEC TOKIN options									26,300	(2,100)	(3,111)
Non-operating (income) expense, net									(2,348)	(4,082)	430
Equity in earnings of subsidiaries									0	0	0
Income (loss) from continuing operations before income taxes and equity income (loss) from NEC TOKIN									(31,217)	(12,126)	(56,297)
Income tax expense (benefit)									6,006	5,227	1,482
Income (loss) from continuing operations before equity income (loss) from NEC TOKIN									(37,223)	(17,353)	(57,779)
Equity income (loss) from NEC TOKIN									(16,406)	(2,169)	(7,090)
Income (loss) from continuing operations	(15,173)	(8,600)	7,194	(37,050)	(19,847)	3,078	7,730	(10,483)	(53,629)	(19,522)	(64,869)
Income (loss) from discontinued operations, net of income tax expense (benefit) of $0, $1,976, and $(98), respectively	0	0	0	0	0	(164)	(1,400)	6,943	0	5,379	(3,634)
Net income (loss)	$ (15,173)	$ (8,600)	$ 7,194	$ (37,050)	$ (19,847)	$ 2,914	$ 6,330	$ (3,540)	(53,629)	(14,143)	(68,503)
Parent
Condensed Financial Statements, Captions [Line Items]
Net sales									0	195	218
Operating costs and expenses:
Cost of sales									1,194	2,468	1,336
Selling, general and administrative expenses									38,071	41,783	41,359
Research and development									79	436	229
Restructuring charges									0	0	0
Write down of long-lived assets											0
Net (gain) loss on sales and disposals of assets									(7)	(10)	0
Gain (Loss) On Inter-company Asset Transfer											0
Total operating costs and expenses									39,337	44,677	42,924
Operating income (loss)									(39,337)	(44,482)	(42,706)
Interest income									0	0	(12)
Interest expense									37,856	38,632	40,069
Change in value of NEC TOKIN options									0	0	0
Non-operating (income) expense, net									(36,183)	(40,903)	(40,642)
Equity in earnings of subsidiaries									12,619	(27,998)	26,332
Income (loss) from continuing operations before income taxes and equity income (loss) from NEC TOKIN									(53,629)	(14,213)	(68,453)
Income tax expense (benefit)									0	(70)	0
Income (loss) from continuing operations before equity income (loss) from NEC TOKIN									(53,629)	(14,143)	(68,453)
Equity income (loss) from NEC TOKIN									0	0	0
Income (loss) from continuing operations									(53,629)	(14,143)	(68,453)
Income (loss) from discontinued operations, net of income tax expense (benefit) of $0, $1,976, and $(98), respectively									0	0	(50)
Net income (loss)									(53,629)	(14,143)	(68,503)
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales									866,163	978,705	966,369
Operating costs and expenses:
Cost of sales									708,143	823,429	878,308
Selling, general and administrative expenses									74,521	70,074	61,896
Research and development									17,313	17,588	16,849
Restructuring charges									2,564	3,310	2,858
Write down of long-lived assets											1,118
Net (gain) loss on sales and disposals of assets									(484)	181	(625)
Gain (Loss) On Inter-company Asset Transfer											14,564
Total operating costs and expenses									802,057	914,582	974,968
Operating income (loss)									64,106	64,123	(8,599)
Interest income									0	0	(4)
Interest expense									1,189	998	1,130
Change in value of NEC TOKIN options									26,300	(2,100)	(3,111)
Non-operating (income) expense, net									34,188	49,069	39,852
Equity in earnings of subsidiaries									0	0	0
Income (loss) from continuing operations before income taxes and equity income (loss) from NEC TOKIN									2,429	16,156	(46,466)
Income tax expense (benefit)									(269)	576	(1,302)
Income (loss) from continuing operations before equity income (loss) from NEC TOKIN									2,698	15,580	(45,164)
Equity income (loss) from NEC TOKIN									(16,406)	(2,169)	(7,090)
Income (loss) from continuing operations									(13,708)	13,411	(52,254)
Income (loss) from discontinued operations, net of income tax expense (benefit) of $0, $1,976, and $(98), respectively									0	102	(1,195)
Net income (loss)									(13,708)	13,513	(53,449)
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net sales									703,690	773,504	817,945
Operating costs and expenses:
Cost of sales									642,362	707,493	729,105
Selling, general and administrative expenses									43,728	46,181	47,643
Research and development									7,563	7,778	7,388
Restructuring charges									1,614	9,707	11,264
Write down of long-lived assets											3,358
Net (gain) loss on sales and disposals of assets									866	(392)	657
Gain (Loss) On Inter-company Asset Transfer											(14,564)
Total operating costs and expenses									696,133	770,767	784,851
Operating income (loss)									7,557	2,737	33,094
Interest income									(14)	(15)	(179)
Interest expense									560	1,071	(237)
Change in value of NEC TOKIN options									0	0	0
Non-operating (income) expense, net									(353)	(12,248)	1,220
Equity in earnings of subsidiaries									0	0	0
Income (loss) from continuing operations before income taxes and equity income (loss) from NEC TOKIN									7,364	13,929	32,290
Income tax expense (benefit)									6,275	4,721	2,784
Income (loss) from continuing operations before equity income (loss) from NEC TOKIN									1,089	9,208	29,506
Equity income (loss) from NEC TOKIN									0	0	0
Income (loss) from continuing operations									1,089	9,208	29,506
Income (loss) from discontinued operations, net of income tax expense (benefit) of $0, $1,976, and $(98), respectively									0	5,277	(2,389)
Net income (loss)									1,089	14,485	27,117
Reclassifications and Eliminations
Condensed Financial Statements, Captions [Line Items]
Net sales									(835,030)	(929,212)	(950,866)
Operating costs and expenses:
Cost of sales									(780,156)	(869,707)	(895,824)
Selling, general and administrative expenses									(54,874)	(59,505)	(55,042)
Research and development									0	0	0
Restructuring charges									0	0	0
Write down of long-lived assets											0
Net (gain) loss on sales and disposals of assets									0	0	0
Gain (Loss) On Inter-company Asset Transfer											0
Total operating costs and expenses									(835,030)	(929,212)	(950,866)
Operating income (loss)									0	0	0
Interest income									0	0	0
Interest expense									0	0	0
Change in value of NEC TOKIN options									0	0	0
Non-operating (income) expense, net									0	0	0
Equity in earnings of subsidiaries									(12,619)	27,998	(26,332)
Income (loss) from continuing operations before income taxes and equity income (loss) from NEC TOKIN									12,619	(27,998)	26,332
Income tax expense (benefit)									0	0	0
Income (loss) from continuing operations before equity income (loss) from NEC TOKIN									12,619	(27,998)	26,332
Equity income (loss) from NEC TOKIN									0	0	0
Income (loss) from continuing operations									12,619	(27,998)	26,332
Income (loss) from discontinued operations, net of income tax expense (benefit) of $0, $1,976, and $(98), respectively									0	0	0
Net income (loss)									$ 12,619	$ (27,998)	$ 26,332