Basis of Financial Statement Presentation (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016
Segment Reporting, Other Significant Reconciling Item, Consolidated [Abstract]
Other Assets			$ 3,068
Total assets	$ 670,980		699,780
Long-term debt, less current portion	385,968		385,833
Liabilities and Equity	670,980		699,780
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Money markets	739		738
Debt, Long-term and Short-term, Combined Amount	(385,968)		(387,833)
Change in value of NEC TOKIN options	12,000	$ 29,200
Inventory, Gross [Abstract]
Raw materials and supplies	78,936		80,289
Work in process	48,478		46,631
Finished goods	55,697		58,060
Inventory, gross	183,111		184,980
Inventory reserves	(15,195)		(16,101)
Inventories, net	$ 167,916		$ 168,879
Warrant
Number of shares subject to a warrant held by K Equity, LLC	8,416,815		8,416,815
Revenue Recognition
Maximum Percentage of Purchased Inventory that Can be Returned by Distributor	6.00%
Period of product warranty	1 year
Warranty costs as a percentage of net sales, maximum	1.00%	1.00%
Reported Value Measurement [Member]
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Derivative Assets (Liabilities), at Fair Value, Net	$ (32,600)		$ (20,600)
Recurring
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Money markets	739		738
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs	(32,600)		(20,600)
Change in value of NEC TOKIN options	12,000
Recurring | Estimate of Fair Value Measurement [Member]
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Total debt	(366,533)		(284,261)
Derivative Assets (Liabilities), at Fair Value, Net	(32,600)		(20,600)
Recurring | Level 1
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Money markets	739		738
Debt, Long-term and Short-term, Combined Amount	(337,115)		(254,713)
Recurring | Level 2
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Money markets	0		0
Debt, Long-term and Short-term, Combined Amount	(29,418)		(29,548)
Recurring | Level 3
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Money markets	0		0
Debt, Long-term and Short-term, Combined Amount	0		0
Restatement Adjustment [Member] | Accounting Standards Update 2015-17 [Member]
Segment Reporting, Other Significant Reconciling Item, Consolidated [Abstract]
Other Assets			(2,764)
Total assets			(2,764)
Long-term debt, less current portion			(2,764)
Liabilities and Equity			(2,764)
Scenario, Previously Reported [Member] | Accounting Standards Update 2015-17 [Member]
Segment Reporting, Other Significant Reconciling Item, Consolidated [Abstract]
Other Assets			5,832
Total assets			702,544
Long-term debt, less current portion			388,597
Liabilities and Equity			702,544
NEC TOKIN Corporation [Member] | Put Option [Member]
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Forward Option Net Asset (Liability) Fair Value	(32,600)		(20,600)
NEC TOKIN Corporation [Member] | Put Option [Member] | Recurring | Level 3
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Change in value of NEC TOKIN options	$ 12,000
Other Noncurrent Assets [Member] | NEC TOKIN Corporation [Member] | Put Option [Member] | Recurring | Level 3
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Forward Option Net Asset (Liability) Fair Value			$ (20,600)