Debt (Details)	3 Months Ended						3 Months Ended				3 Months Ended				3 Months Ended
	Jun. 30, 2013 USD ($)	Jun. 30, 2012 USD ($)	Mar. 31, 2013 USD ($)	Aug. 28, 2012 USD ($)	Jun. 30, 2013 10.5% Senior Notes USD ($)	Mar. 31, 2013 10.5% Senior Notes USD ($)	Jun. 30, 2013 Advanced payment from OEM OEM USD ($)	Mar. 31, 2013 Advanced payment from OEM OEM USD ($)	Oct. 08, 2012 Advanced payment from OEM OEM USD ($)	Aug. 28, 2012 Advanced payment from OEM OEM USD ($)	Jun. 30, 2013 Advanced payment from OEM OEM Maximum USD ($)	Jun. 30, 2013 Advanced payment from OEM OEM Minimum USD ($)	Jun. 30, 2013 Other USD ($)	Mar. 31, 2013 Other USD ($)	Jun. 30, 2013 Revolving Line of Credit USD ($)	Jun. 30, 2013 Revolving Line of Credit EUR (€)
Debt
Total debt	$ 383,293,000		$ 383,500,000		$ 358,620,000	$ 358,773,000	$ 22,856,000	$ 22,944,000					$ 1,817,000	$ 1,783,000
Current maturities	(7,648,000)		(10,793,000)
Total long-term debt	375,645,000		372,707,000
Stated interest rate (as a percent)					10.50%	10.50%
Unamortized premium					3,620,000	3,773,000
Unamortized discount							840,000	1,056,000
Interest expense
Contractual interest expense	9,020,000	9,486,000
Amortization of debt issuance costs	426,000	426,000
Amortization of debt (premium) discount	62,000	(153,000)
Imputed interest on acquisition related obligations	526,000	698,000
Total interest expense	10,034,000	10,457,000
Amount agreed to be advanced				24,000,000						24,000,000
Aggregate principal amount					355,000,000	355,000,000	23,700,000	24,000,000
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%
Amount of irrevocable standby letter of credit delivered									16,000,000
Cash balance to be maintained on last day of any fiscal quarter												60,000,000
Percentage of consolidated total assets accounted by subsidiary which applies for bankruptcy or other similar proceedings												20.00%
Period within which any proceeding filed against the entity is to be dismissed											60 days
Amount outstanding					355,000,000	355,000,000
Interest payable					6,200,000	15,600,000
Maximum borrowing capacity															50,000,000
Letter of credit issued															1,400,000	1,100,000
Remaining borrowing capacity															$ 23,700,000