Restructuring Charges (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Restructuring Charges
Restructuring charges	$ 1,830	$ 4,610
Reconciliation of restructuring liability
Costs charged to expense	1,830	4,610
Solid Capacitors
Restructuring Charges
Restructuring charges	1,230	3,045
Reconciliation of restructuring liability
Costs charged to expense	1,230	3,045
Manufacturing relocation costs
Restructuring Charges
Restructuring charges	1,684	475
Reconciliation of restructuring liability
Beginning of period		567
Costs charged to expense	1,684	475
Costs paid or settled	(1,684)	(1,042)
Manufacturing relocation costs | Europe [Member] | Solid Capacitors
Restructuring Charges
Restructuring charges	1,700
Reconciliation of restructuring liability
Costs charged to expense	1,700
Manufacturing relocation costs | Italy and Evora Portugal [Member]
Restructuring Charges
Restructuring charges	500
Reconciliation of restructuring liability
Costs charged to expense	500
Personnel reduction costs
Restructuring Charges
Restructuring charges	146	4,135
Reconciliation of restructuring liability
Beginning of period	6,217	13,509
Costs charged to expense	146	4,135
Costs paid or settled	(2,924)	(8,869)
Change in foreign exchange	(55)	172
End of period	3,384	8,947
Personnel reduction costs | Innovation center
Restructuring Charges
Restructuring charges		1,900
Reconciliation of restructuring liability
Costs charged to expense		1,900
Personnel reduction costs | Europe [Member] | Solid Capacitors
Restructuring Charges
Restructuring charges	100
Reconciliation of restructuring liability
Costs charged to expense	100
Personnel reduction costs | Mexican operations | Solid Capacitors
Restructuring Charges
Restructuring charges		1,100
Reconciliation of restructuring liability
Costs charged to expense		1,100
Personnel reduction costs | Italy
Restructuring Charges
Restructuring charges		700
Reconciliation of restructuring liability
Costs charged to expense		700
Personnel reduction costs | CIGS Plan
Restructuring Charges
Restructuring charges		400
Reconciliation of restructuring liability
Costs charged to expense		$ 400
Personnel reduction costs | CIGS Plan | Maximum
Restructuring Charges
Number of employees covered under Cassia Integrazione Guadagni Straordinaria plan		170
Term of Cassia Integrazione Guadagni Straordinaria plan		12 months