Investment in NEC TOKIN - Summarized Financial Information (Details) - NEC TOKIN Corporation [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2016
Equity Method Investment, Summarized Financial Information, Assets [Abstract]
Current assets	$ 249,818		$ 249,818		$ 240,427
Non-current assets	258,333		258,333		260,614
Equity Method Investment, Summarized Financial Information, Liabilities and Equity [Abstract]
Current liabilities	171,193		171,193		179,360
Non-current liabilities	368,011		368,011		$ 335,500
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Sales	126,589	$ 117,358	247,099	$ 232,092
Gross profit	27,055	25,055	53,601	49,723
Net income (loss)	$ 2,012	$ 2,007	$ 4,362	$ 7,261