Investment in NEC TOKIN (Details) $ in Thousands		3 Months Ended
	Feb. 01, 2013 USD ($) director_position	Jun. 30, 2015 USD ($) number_of_times	Jun. 30, 2014 USD ($)	Mar. 31, 2015 USD ($)	Mar. 12, 2012
Schedule of Equity Method Investments [Line Items]
Document Period End Date		Jun. 30, 2015
Change in value of NEC TOKIN options		$ (29,200)	$ 4,100
Reported Value Measurement [Member]
Schedule of Equity Method Investments [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net		(23,500)		$ 5,700
Recurring
Schedule of Equity Method Investments [Line Items]
Change in value of NEC TOKIN options		(29,200)
NEC TOKIN
Schedule of Equity Method Investments [Line Items]
Accounts Payable, Related Parties, Current		$ 471		765
Economic ownership to be acquired (as a percent)		34.00%	34.00%
Summarized financial information
Current assets		$ 225,284		223,495
Non-current assets		266,048		273,785
Current liabilities		141,405		143,523
Non-current liabilities		289,731		$ 296,873
Sales		114,734	$ 122,408
Gross profit		24,668	26,678
Net income (loss)		5,255	$ (3,154)
Stockholders' Agreement | NEC TOKIN
Schedule of Equity Method Investments [Line Items]
Number of director positions | director_position	7
Put Option | NEC TOKIN
Schedule of Equity Method Investments [Line Items]
Change in value of NEC TOKIN options		$ (29,200)
Senior Notes
Schedule of Equity Method Investments [Line Items]
Interest rate of senior notes (as a percent)		10.50%		10.50%
KEC | NEC TOKIN
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Aggregate Cost	$ 54,500
Summarized financial information
Business Acquisition, Transaction Costs	4,500
KEC | Stock Purchase Agreement | NEC TOKIN
Schedule of Equity Method Investments [Line Items]
Common stock acquired (as a percent)					51.00%
Economic ownership to be acquired (as a percent)					34.00%
Purchase price paid	$ 50,000
KEC | Stockholders' Agreement
Schedule of Equity Method Investments [Line Items]
Due from Related Parties, Current		$ 593		$ 572
KEC | Stockholders' Agreement | NEC TOKIN
Schedule of Equity Method Investments [Line Items]
Number of director positions | director_position	4
KEC | Option Agreement | NEC TOKIN
Schedule of Equity Method Investments [Line Items]
Economic ownership to be acquired (as a percent)		49.00%
Purchase price for expected additional shares that may be acquired		$ 50,000
Ownership interest maintained after acquisition of additional shares (as a percent)		51.00%
LTM EBITDA multiple | number_of_times		6
KEC | Put Option | NEC TOKIN
Schedule of Equity Method Investments [Line Items]
LTM EBITDA multiple | number_of_times		6
Level 3 | Recurring
Schedule of Equity Method Investments [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net				5,700
Level 3 | Recurring | Reported Value Measurement [Member]
Schedule of Equity Method Investments [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net		$ (23,500)		$ 5,700