Investment in NEC TOKIN (Details) (USD $)	6 Months Ended		6 Months Ended		6 Months Ended			0 Months Ended			6 Months Ended
	Sep. 30, 2013	Sep. 30, 2013 KEC Stockholders' Agreement	Sep. 30, 2013 NEC TOKIN	Feb. 01, 2013 NEC TOKIN Stockholders' Agreement item	Sep. 30, 2013 NEC TOKIN Put Option	Mar. 31, 2013 NEC TOKIN Put Option	Feb. 01, 2013 NEC TOKIN KEC	Feb. 01, 2013 NEC TOKIN KEC Stock Purchase Agreement	Mar. 12, 2012 NEC TOKIN KEC Stock Purchase Agreement	Feb. 01, 2013 NEC TOKIN KEC Stockholders' Agreement item	Sep. 30, 2013 NEC TOKIN KEC Option Agreement item	Sep. 30, 2013 NEC TOKIN KEC Put Option item
Investment in NEC TOKIN
Common stock acquired (as a percent)									51.00%
Economic ownership to be acquired (as a percent)									34.00%		49.00%
Purchase price							$ 54,500,000
Purchase price paid								50,000,000
Number of director positions				7						4
Purchase price for expected additional shares that may be acquired											50,000,000
Ownership interest maintained after acquisition of additional shares (as a percent)											51.00%
LTM EBITDA multiple											6	6
NEC TOKIN options, net					106,000	489,000
Loss recognized included in the Other expense, net	383,000				383,000
Transaction expenses							4,500,000
Summarized financial information
Current assets			230,061,000
Noncurrent assets			391,929,000
Current liabilities			133,267,000
Noncurrent liabilities			397,422,000
Sales			258,266,000
Gross profit			43,869,000
Net loss			(11,942,000)
Excess of the carrying value for its investment over equity in memo accounts			15,900,000
Net sales			1,900,000
Accounts receivable			200,000
Accounts payable			100,000
Receivable balances		$ 700,000