Debt (Details) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Mar. 31, 2014	Aug. 31, 2012
Summarized information about the term loan [Abstract]
Less current portion of term loan	$ (7,843,000)		$ (7,843,000)		$ (7,843,000)
Long-term portion of term loan	75,846,000		75,846,000		79,434,000
Future repayments of the Term Loan, by fiscal year [Abstract]
Total (gain) loss included in net loss			275,000	3,961,000
Financing Agreement [Member]
Maximum amount of capital expenditures by fiscal year [Abstract]
2015	7,000,000		7,000,000
2016	4,000,000		4,000,000
2017	4,000,000		4,000,000
Financing Agreement [Member] | Term Loans [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	95,000,000		95,000,000
Debt instrument, maturity date			Nov. 06, 2018
Maximum amount of equity interests that may be repurchased	10,000,000		10,000,000
Maximum amount of capital expenditures by fiscal year [Abstract]
Quarterly principal payments			2,100,000
Reference interest rate under option 1			LIBOR
Reference interest rate under option 1, floor (in hundredths)	1.50%		1.50%
Interest rate over LIBOR rate under option 1 (in hundredths)			5.25%
Interest rate above base rate under option 2 (in hundredths)	4.25%		4.25%
Interest rate at end of period using LIBOR option (in hundredths)	6.75%		6.75%		6.75%
Summarized information about the term loan [Abstract]
Principal amount of term loan	88,700,000		88,700,000		92,900,000
Unamortized financing fees	(5,011,000)		(5,011,000)		(5,623,000)
Net carrying amount of term loan	83,689,000		83,689,000		87,277,000
Less current portion of term loan	(7,843,000)		(7,843,000)		(7,843,000)
Long-term portion of term loan	75,846,000		75,846,000		79,434,000
Future repayments of the Term Loan, by fiscal year [Abstract]
2015 - remaining six months	4,200,000		4,200,000
2016	8,400,000		8,400,000
2017	8,400,000		8,400,000
2018	8,400,000		8,400,000
2019	59,300,000		59,300,000
Prepayment penalty (in hundredths)			2.00%
Financing Agreement [Member] | Revolving Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	30,000,000		30,000,000
Debt instrument, maturity date			Nov. 06, 2018
Maximum amount of capital expenditures by fiscal year [Abstract]
Reference interest rate under option 1			LIBOR
Interest rate over LIBOR rate under option 1 (in hundredths)			2.50%
Interest rate above base rate under option 2 (in hundredths)	1.00%		1.00%
Interest rate at end of period using LIBOR option (in hundredths)					2.66%
Future repayments of the Term Loan, by fiscal year [Abstract]
Outstanding balance under revolving loan	0		0		10,000,000
Amount available under revolving facility	38,876,000		38,876,000
Financing Agreement [Member] | Revolving Facility [Member] | Letter of Credit [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	10,000,000		10,000,000
Financing Agreement [Member] | Revolving Facility [Member] | Commercial Letter of Credit [Member]
Future repayments of the Term Loan, by fiscal year [Abstract]
Outstanding balance under revolving loan	694,000		694,000
Financing Agreement [Member] | Revolving Facility [Member] | Standby Letters of Credit [Member]
Future repayments of the Term Loan, by fiscal year [Abstract]
Outstanding balance under revolving loan	430,000		430,000
Financing Agreement [Member] | First Amendment [Member] | Revolving Facility [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	40,000,000		40,000,000
Increase (decrease) in maximum borrowing capacity	10,000,000		10,000,000
WX Agreement [Member] | Supplier Warrant [Member]
Future repayments of the Term Loan, by fiscal year [Abstract]
Number of shares that can be purchased under warrants (in shares)						516,129
Initial exercise price (in dollars per share)						$ 7.75
Fair value of warrants issued	10,322,000		10,322,000		10,047,000
Total (gain) loss included in net loss	$ (1,389,000)	$ (1,782,000)	$ (275,000)	$ (2,922,000)