Restructuring Charges (Details) (USD $)	3 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Restructuring Charges
Restructuring charges	$ 4,610,000	$ 1,264,000
Reconciliation of restructuring liability
Costs charged to expense	4,610,000	1,264,000
Solid Capacitors
Restructuring Charges
Restructuring charges	3,045,000	142,000
Reconciliation of restructuring liability
Costs charged to expense	3,045,000	142,000
Manufacturing relocation costs
Restructuring Charges
Restructuring charges	475,000	146,000
Reconciliation of restructuring liability
Balance at the beginning of the period	567,000
Costs charged to expense	475,000	146,000
Costs paid or settled	(1,042,000)
Manufacturing relocation costs | China and Macedonia
Restructuring Charges
Restructuring charges		200,000
Reconciliation of restructuring liability
Costs charged to expense		200,000
Manufacturing relocation costs | Italy and Evora, Portugal
Restructuring Charges
Restructuring charges	500,000
Reconciliation of restructuring liability
Costs charged to expense	500,000
Personnel reduction costs
Restructuring Charges
Restructuring charges	4,135,000	1,118,000
Workforce reductions related to administrative overhead	700,000
Reconciliation of restructuring liability
Balance at the beginning of the period	13,509,000
Costs charged to expense	4,135,000	1,118,000
Costs paid or settled	(8,869,000)
Change in foreign exchange	172,000
Balance at the end of the period	8,947,000
Personnel reduction costs | Innovation center
Restructuring Charges
Restructuring charges	1,900,000
Reconciliation of restructuring liability
Costs charged to expense	1,900,000
Personnel reduction costs | Mexican operations | Solid Capacitors
Restructuring Charges
Restructuring charges	1,100,000
Reconciliation of restructuring liability
Costs charged to expense	1,100,000
Personnel reduction costs | Italy
Restructuring Charges
Restructuring charges	400,000
Reconciliation of restructuring liability
Costs charged to expense	$ 400,000
Personnel reduction costs | Italy | Maximum
Restructuring Charges
Number of employees covered under Cassia Integrazione Guadagni Straordinaria plan	170
Term of Cassia Integrazione Guadagni Straordinaria plan	12 months