Segment and Geographic Information (Details) (USD $)	3 Months Ended		9 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 business_group	Dec. 31, 2012	Mar. 31, 2013
Segment Reporting [Abstract]
Number of business groups			2
Segment and geographic information
Net sales	$ 207,339,000	$ 197,698,000	$ 617,845,000	$ 624,363,000
Operating income (loss)	3,623,000	(3,412,000)	(13,004,000)	(20,551,000)
Depreciation and amortization expenses	11,759,000	10,405,000	37,352,000	33,389,000
Restructuring charges included in Operating income (loss)
Restructuring charges	2,194,000	3,886,000	8,169,000	13,672,000
Write down of long-lived assets	3,358,000	3,084,000	3,358,000	7,318,000
Goodwill impairment				1,092,000
Assets
Total assets	862,325,000		862,325,000		911,591,000
Discontinued operations
Assets
Total assets	10,779,000		10,779,000		11,233,000
North and South America ("Americas")
Segment and geographic information
Net sales	67,875,000	61,255,000	192,625,000	182,684,000
Europe, Middle East, Africa ("EMEA")
Segment and geographic information
Net sales	68,026,000	65,081,000	209,183,000	212,473,000
Asia and Pacific Rim ("APAC")
Segment and geographic information
Net sales	71,438,000	71,362,000	216,037,000	229,206,000
Unallocated/Corporate
Segment and geographic information
Operating income (loss)	(21,619,000)	(22,615,000)	(67,911,000)	(70,827,000)
Depreciation and amortization expenses	1,601,000	1,080,000	4,983,000	3,195,000
Restructuring charges included in Operating income (loss)
Restructuring charges	3,000		361,000
Assets
Total assets	78,907,000		78,907,000		85,816,000
Solid Capacitors
Segment and geographic information
Number of manufacturing sites			10
Net sales	156,082,000	149,772,000	463,197,000	472,940,000
Operating income (loss)	27,616,000	24,757,000	65,795,000	73,325,000
Depreciation and amortization expenses	6,798,000	6,091,000	21,409,000	20,616,000
Restructuring charges included in Operating income (loss)
Restructuring charges	91,000	2,030,000	3,235,000	5,389,000
Write down of long-lived assets	2,800,000	3,100,000	2,800,000	3,100,000
Net curtailment and settlement gain (loss) on benefit plans		(400,000)		(400,000)
Assets
Total assets	483,352,000		483,352,000		517,024,000
Film and Electrolytic
Segment and geographic information
Number of manufacturing sites			15
Net sales	51,257,000	47,926,000	154,648,000	151,423,000
Operating income (loss)	(2,374,000)	(5,554,000)	(10,888,000)	(23,049,000)
Depreciation and amortization expenses	3,360,000	3,234,000	10,960,000	9,578,000
Restructuring charges included in Operating income (loss)
Restructuring charges	2,100,000	1,856,000	4,573,000	8,283,000
Write down of long-lived assets	600,000		600,000	4,200,000
Goodwill impairment				1,100,000
Net curtailment and settlement gain (loss) on benefit plans				1,500,000
Assets
Total assets	$ 289,287,000		$ 289,287,000		$ 297,518,000