Fair Value Measurements - Schedule of Liabilities Measured at Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Sep. 30, 2014	Mar. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Ending balance	$ 1,841	$ 2,601
Warrants
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance	2,601	3,633
Warrant issuance with Senior Secured Term Loan		315
Mark to market adjustment	(760)	(1,347)
Extinguishment of derivative liability		0
Ending balance	1,841	2,601
Derivative Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Beginning balance		529
Warrant issuance with Senior Secured Term Loan		0
Mark to market adjustment		(525)
Extinguishment of derivative liability		(4)
Ending balance		$ 0