Impairment Charges Impairment Charges - Narrative (Details) - USD ($)	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Property, Plant and Equipment [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 0	$ 0	$ 4,476,000
Solid Capacitors
Property, Plant and Equipment [Line Items]
Impairment of Long-Lived Assets Held-for-use		$ 3,900,000
Impairment Effect on Earnings Per Share, Pretax		$ 0.09
Film and Electrolytic
Property, Plant and Equipment [Line Items]
Impairment of Long-Lived Assets Held-for-use		$ 600,000
Impairment Effect on Earnings Per Share, Pretax		$ 0.01