Debt (Details)	3 Months Ended		6 Months Ended						6 Months Ended				6 Months Ended			12 Months Ended	6 Months Ended						6 Months Ended		6 Months Ended
	Sep. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)	Mar. 31, 2014 USD ($)	Aug. 28, 2012 USD ($)	Sep. 30, 2014 10.5% Senior Notes, net of premium of $2,807 and $3,144 as of September 30, 2014 and March 31, 2014, respectively USD ($)	Mar. 31, 2014 10.5% Senior Notes, net of premium of $2,807 and $3,144 as of September 30, 2014 and March 31, 2014, respectively USD ($)	Sep. 30, 2014 Advanced payment from OEM, net of discount of $111 and $323 as of September 30, 2014 and March 31, 2014, respectively USD ($)	Mar. 31, 2014 Advanced payment from OEM, net of discount of $111 and $323 as of September 30, 2014 and March 31, 2014, respectively USD ($)	Oct. 08, 2012 Advanced payment from OEM, net of discount of $111 and $323 as of September 30, 2014 and March 31, 2014, respectively USD ($)	Aug. 28, 2012 Advanced payment from OEM, net of discount of $111 and $323 as of September 30, 2014 and March 31, 2014, respectively USD ($)	Sep. 30, 2014 Advanced payment from OEM, net of discount of $111 and $323 as of September 30, 2014 and March 31, 2014, respectively Minimum USD ($)	Sep. 30, 2014 Advanced payment from OEM, net of discount of $111 and $323 as of September 30, 2014 and March 31, 2014, respectively Maximum USD ($)	Sep. 30, 2014 Revolving Line of Credit USD ($)	Mar. 31, 2014 Revolving Line of Credit USD ($) letters_of_credit	Sep. 30, 2014 Letters of Credit One USD ($)	Mar. 31, 2014 Letters of Credit Two USD ($)	Mar. 31, 2014 Letters of Credit Two EUR (€)	Mar. 31, 2014 Letter of Credit Three USD ($)	Mar. 31, 2014 Letter of Credit Three EUR (€)	Sep. 30, 2014 US Facility USD ($)	Sep. 30, 2014 US Facility Base Rate	Sep. 30, 2014 Singapore Facility USD ($)	Sep. 30, 2014 Singapore Facility LIBOR	Sep. 30, 2014 Other USD ($)	Mar. 31, 2014 Other USD ($)
Debt
Long-term debt outstanding							$ 355,000,000	$ 355,000,000	$ 18,600,000	$ 20,400,000
Revolving line of credit															25,249,000	18,449,000						13,200,000		12,000,000
Total debt	402,082,000		402,082,000		398,589,000		357,807,000	358,144,000	18,486,000	20,095,000																540,000	1,901,000
Current maturities	(25,826,000)		(25,826,000)		(7,297,000)
Total long-term debt	376,256,000		376,256,000		391,292,000
Interest expense
Contractual interest expense	9,659,000	8,963,000	19,411,000	17,983,000
Amortization of debt issuance costs	426,000	426,000	852,000	852,000
Amortization of debt (premium) discount	(78,000)	42,000	(126,000)	104,000
Imputed interest on acquisition related obligations	235,000	477,000	522,000	1,003,000
Interest expense on capital lease	45,000	0	84,000	0
Total interest expense	10,287,000	9,908,000	20,743,000	19,942,000
Maximum borrowing capacity															50,000,000
Stated interest rate (as a percent)							10.50%	10.50%															5.25%		3.50%
Spread on variable rate basis (as a percent)																							2.25%		3.25%
Term on borrowing															31 days
Amount borrowed																	14,300,000
Repayments of lines of credit			7,500,000	0													7,500,000
Remaining borrowing capacity																	300,000
Amount of irrevocable standby letter of credit delivered											16,000,000						16,000,000	1,400,000	1,100,000	900,000	700,000
Number of letters of credit																2
Amount agreed to be advanced						24,000,000						24,000,000
Monthly repayment of advanced amount, price ratio below threshold														1,000,000.0
Monthly repayment of advanced amount, price ratio above threshold														2,000,000.0
Threshold price ratio (as a percent)									110.00%
Cash balance to be maintained on last day of any fiscal quarter													60,000,000.0
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
Interest payable							15,500,000	15,500,000
Debt instrument, unamortized premium							2,807,000	3,144,000
Debt instrument, unamortized discount									$ 111,000	$ 323,000