Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Statement of Cash Flows [Abstract]
Net income (loss)	$ (17,203)	$ (29,856)
Operating Activities:
Depreciation and amortization	18,876	19,182
Equity income (loss) from NEC TOKIN	(404)	(1,747)
Non-cash debt and financing costs	378	437
Stock-based compensation expense	2,332	2,607
Change in value of NEC TOKIN option	10,400	27,000
Net (gain) loss on sales and disposals of assets	175	(362)
Write down of long-lived assets	6,193	0
Pension and other post-retirement benefits	1,417	333
Change in deferred income taxes	1,165	52
Change in operating assets	1,721	(14,474)
Change in operating liabilities	(1,830)	(14,514)
Other	(177)	410
Net cash provided by (used in) operating activities	23,043	(10,932)
Investing activities:
Capital expenditures	(10,344)	(9,268)
Acquisitions, net of cash received	0	(2,892)
Proceeds from sale of assets	0	247
Net cash provided by (used in) investing activities	(10,344)	(11,913)
Financing activities:
Proceeds from revolving line of credit	0	8,000
Payments of revolving line of credit	0	(3,500)
Payments on long-term debt	(1,870)	(481)
Purchase of treasury stock	(628)	(575)
Net cash provided by (used in) financing activities	(2,498)	3,444
Net increase (decrease) in cash and cash equivalents	10,201	(19,401)
Effect of foreign currency fluctuations on cash	(452)	354
Cash and cash equivalents at beginning of fiscal period	65,004	56,362
Cash and cash equivalents at end of fiscal period	$ 74,753	$ 37,315