Consolidated Statements of Operations - USD ($) shares 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
Income Statement [Abstract]
Net sales	$ 183,926,000	$ 177,184,000	$ 186,123,000	$ 187,590,000	$ 193,708,000	$ 201,310,000	$ 215,293,000	$ 212,881,000	$ 734,823,000	$ 823,192,000	$ 833,666,000
Operating costs and expenses:
Cost of sales									571,543,000	663,683,000	712,925,000
Selling, general and administrative expenses									101,446,000	98,533,000	95,856,000
Research and development									24,955,000	25,802,000	24,466,000
Restructuring charges									4,178,000	13,017,000	14,122,000
Impairment of Long-Lived Assets Held-for-use									0	0	4,476,000
Net (gain) loss on sales and disposals of assets									375,000	(221,000)	32,000
Total operating costs and expenses									702,497,000	800,814,000	851,877,000
Operating income (loss)	8,603,000	8,493,000	13,987,000	1,243,000	912,000	9,302,000	12,770,000	(606,000)	32,326,000	22,378,000	(18,211,000)
Other (income) expense:
Interest income									(14,000)	(15,000)	(195,000)
Interest expense									39,605,000	40,701,000	40,962,000
Change in value of NEC TOKIN options									26,300,000	(2,100,000)	(3,111,000)
Non-operating (income) expense, net									(2,348,000)	(4,082,000)	430,000
Income (loss) from continuing operations before income taxes and equity income (loss) from NEC TOKIN									(31,217,000)	(12,126,000)	(56,297,000)
Income tax expense (benefit)									6,006,000	5,227,000	1,482,000
Income (loss) from continuing operations before equity income (loss) from NEC TOKIN									(37,223,000)	(17,353,000)	(57,779,000)
Equity income (loss) from NEC TOKIN									(16,406,000)	(2,169,000)	(7,090,000)
Income (loss) from continuing operations	(15,173,000)	(8,600,000)	7,194,000	(37,050,000)	(19,847,000)	3,078,000	7,730,000	(10,483,000)	(53,629,000)	(19,522,000)	(64,869,000)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0	0	0	0	0	(164,000)	(1,400,000)	6,943,000	0	5,379,000	(3,634,000)
Net income (loss)	$ (15,173,000)	$ (8,600,000)	$ 7,194,000	$ (37,050,000)	$ (19,847,000)	$ 2,914,000	$ 6,330,000	$ (3,540,000)	$ (53,629,000)	$ (14,143,000)	$ (68,503,000)
Net income (loss) per basic share:
Loss from continuing operations (in dollars per share)	$ (0.33)	$ (0.19)	$ 0.16	$ (0.81)	$ (0.44)	$ 0.07	$ 0.17	$ (0.23)	$ (1.17)	$ (0.43)	$ (1.44)
Income (loss) from discontinued operations (in dollars per share)	0.00	0.00	0.00	0.00	0.00	0.00	(0.03)	0.15	0.00	0.12	(0.08)
Net income (loss) (in dollars per share)	(0.33)	(0.19)	0.16	(0.81)	(0.44)	0.07	0.14	(0.08)	(1.17)	(0.31)	(1.52)
Net income (loss) per diluted share:
Loss from continuing operations (in dollars per share)	(0.33)	(0.19)	0.14	(0.81)	(0.44)	0.06	0.15	(0.23)	(1.17)	(0.43)	(1.44)
Income (loss) from discontinued operations (in dollars per share)	0.00	0.00	0.00	0.00	0.00	0.00	(0.03)	0.15	0.00	0.12	(0.08)
Net income (loss) (in dollars per share)	$ (0.33)	$ (0.19)	$ 0.14	$ (0.81)	$ (0.44)	$ 0.06	$ 0.12	$ (0.08)	$ (1.17)	$ (0.31)	$ (1.52)
Weighted-average shares outstanding:
Basic (in shares)									46,004	45,381	45,102
Diluted (in shares)									46,004	45,381	45,102