Income Taxes - Provision (Benefit) for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Components of Income (loss) before income taxes
Domestic (U.S.)	$ 653	$ (38,581)	$ (26,238)
Foreign (Outside U.S.)	9,983	7,364	14,112
Income (loss) from continuing operations before income taxes and equity income (loss) from TOKIN	10,636	(31,217)	(12,126)
Current:
Federal	0	0	0
State and local	62	95	(92)
Foreign	4,247	5,416	7,403
Total current income tax expense from continuing operations	4,309	5,511	7,311
Deferred:
Federal	(6)	(647)	270
State and local	(97)	172	39
Deferred Foreign Income Tax Expense (Benefit)	84	970	(2,393)
Deferred tax expense (benefit) from continuing operations	(19)	495	(2,084)
Provision for income taxes	4,290	6,006	5,227
Latest Tax Year [Member]
Deferred:
Deferred Foreign Income Tax Expense (Benefit)	$ 1,200	$ 1,400	$ (2,100)