Debt (Details) (USD $)	3 Months Ended		9 Months Ended			0 Months Ended		0 Months Ended	1 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Mar. 31, 2012	Aug. 28, 2012 OEM	Oct. 08, 2012 OEM	Aug. 28, 2012 OEM Maximum	Apr. 30, 2012 10.5% Senior Notes	Mar. 31, 2012 10.5% Senior Notes	May 31, 2010 10.5% Senior Notes	Dec. 31, 2012 10.5% Senior Notes	Apr. 03, 2012 10.5% Senior Notes	Mar. 27, 2012 10.5% Senior Notes	Dec. 31, 2012 Other	Mar. 31, 2012 Other	Dec. 31, 2012 Revolving Line of Credit	Mar. 31, 2012 Revolving Line of Credit	Sep. 30, 2010 Revolving Line of Credit	Sep. 30, 2010 Singapore facility	Dec. 31, 2012 Advanced payment from OEM
Debt
Total debt	$ 383,495,000		$ 383,495,000		$ 347,331,000					$ 343,539,000		$ 358,920,000			$ 1,845,000	$ 3,792,000					$ 22,730,000
Current maturities	(7,908,000)		(7,908,000)		(1,951,000)
Total long-term debt	375,587,000		375,587,000		345,380,000
Stated interest rate (as a percent)										10.50%		10.50%
Unamortized premium										3,539,000		3,920,000
Unamortized discount																					1,270,000
Interest expense
Contractual interest expense	9,125,000	6,189,000	27,794,000	18,815,000
Amortization of debt issuance costs	426,000	274,000	1,278,000	829,000
Amortization of debt (premium) discount	48,000	415,000	(250,000)	1,669,000
Imputed interest on acquisition related obligations	648,000	158,000	2,018,000	405,000
Total interest expense	10,247,000	7,036,000	30,840,000	21,718,000
Amount agreed to be advanced						24,000,000
Period of payment of advanced amount as percentage of aggregate purchase price of capacitors						8 months
Monthly repayment of advanced amount, price ratio below threshold								1,000,000
Monthly repayment of advanced amount, price ratio above threshold								2,000,000
Threshold price ratio (as a percent)						110.00%
Period after which outstanding balance of advance payment is due in full						32 months
Amount of irrevocable standby letter of credit delivered							16,000,000
Aggregate principal amount									15,000,000	110,000,000	230,000,000
Issue price as percentage of principal amount plus accrued interest													105.50%	105.50%
Debt issuance cost, net of amortization										7,800,000		7,100,000					700,000	900,000
Interest payable										14,700,000		6,200,000
Maximum borrowing capacity																			$ 50,000,000	$ 30,000,000