Income Taxes - Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Components of Income (loss) before income taxes
Domestic (U.S.)	$ (38,581)	$ (26,238)	$ (89,529)
Foreign (Outside U.S.)	7,364	14,112	33,232
Income (loss) from continuing operations before income taxes and equity income (loss) from NEC TOKIN	(31,217)	(12,126)	(56,297)
Current:
Federal	0	0	0
State and local	95	(92)	35
Foreign	5,416	7,403	7,816
Total current income tax expense from continuing operations	5,511	7,311	7,851
Deferred:
Federal	(647)	270	(1,694)
State and local	172	39	406
Deferred Foreign Income Tax Expense (Benefit)	970	(2,393)	(5,081)
Deferred tax expense (benefit) from continuing operations	495	(2,084)	(6,369)
Provision for income taxes	6,006	5,227	1,482
Latest Tax Year [Member]
Deferred:
Deferred Foreign Income Tax Expense (Benefit)	$ 1,400	$ (2,100)	$ (2,700)