Debt	12 Months Ended
Mar. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt Senior Secured Term Loans On November 15, 2013, the Company amended its existing Loan and Security Agreement with Hercules, and entered into a term loan (the “Term Loan B”), borrowing $10.0 million. After closing fees and expenses, the net proceeds to the Company for the Term Loan B were $9.8 million. The Term Loan B bore an interest rate of 11% plus the percentage, if any, by which the prime rate as reported by the Wall Street Journal exceeds 3.75%. The Company repaid the Term Loan B in equal monthly installments ending on November 1, 2016, when the loan was repaid in full. The Company paid an end of term fee of $0.5 million upon the maturity of the Term Loan B, which had been accrued at inception of the loan with a corresponding amount recorded into the debt discount. In addition, the Company incurred $0.2 million of legal and origination costs at the inception of the loan, which have been recorded as a debt discount. On December 19, 2014, the Company entered into a second amendment with Hercules (the “Hercules Second Amendment”) and entered into a new term loan, borrowing an additional $1.5 million (the “Term Loan C”). After closing fees and expenses, the net proceeds to the Company for the Term Loan C were $1.4 million. The Term Loan C is also referred to as the “Term Loan”. The Term Loan C also bears the same interest rate as the Term Loan B, which increased to 11.25% effective March 16, 2017. The Company will make interest only payments until maturity on June 1, 2017, when the loan is scheduled to be repaid in its entirety. The maturity date of the Term Loan C was extended from March 1, 2017 to June 1, 2017 due to the Company’s April 2015 equity offering which raised more than $10 million in new capital before December 31, 2015. The Company will pay an end of term fee of approximately $0.1 million upon earlier of maturity or prepayment of the Term Loan C. The Company has accrued the end of term fee and recorded a corresponding amount in the debt discount. The Term Loan C includes a mandatory prepayment feature that allows Hercules the right to use any of the Company's net proceeds from specified asset dispositions greater than $1.0 million in a calendar year to pay off any outstanding accrued interest and principle balances on the Term Loan C. The Company determined the fair value to be de-minimus for this feature. In addition, the Company incurred approximately $0.1 million of legal and origination costs in the three months ended December 31, 2014, which have been recorded as a debt discount. Hercules received warrants to purchase 13,927 shares of common stock (the “First Warrant”) and 25,641 shares of common stock (the “Second Warrant”) in conjunction with a prior term loan which has been repaid in full and the Term Loan B. Due to certain adjustment provisions within the warrants, they qualified for liability accounting and the fair value of the warrants $0.4 million and $0.2 million, respectively, was recorded upon issuance to debt discount and a warrant liability. In conjunction with the Hercules Second Amendment, the First Warrant and Second Warrant were canceled and replaced with the issuance of a new warrant (the “Hercules Warrant”) to purchase 58,823 shares of common stock at an exercise price of $11.00 per share, subject to adjustment. The Warrant expires on June 30, 2020. See Note 10, “Warrants and Derivative Liabilities”, for a discussion on the Warrant and the valuation assumptions used. Under Term Loan B, the total debt discount including the Warrant, end of term fee and legal and origination costs of $1.0 million was amortized into interest expense over the term of the Term Loan B using the effective interest method. During the years ended March 31, 2017 and 2016, the Company recorded non-cash interest expense for amortization of the debt discount related to the Term Loan B of less than $0.1 million and $0.2 million, respectively. Under Term Loan C, the total debt discount, including the Warrant, end of term fee and legal and origination costs of $0.3 million is being amortized into interest expense over the term of the Term Loan C using the effective interest method. During each of the fiscal years ended March 31, 2017 and 2016, the Company recorded non-cash interest expense for amortization of the debt discount related to the Term Loan C of $0.1 million. The Term Loan is secured by substantially all of the Company’s existing and future assets, including a mortgage on real property owned by the Company’s wholly-owned subsidiary, ASC Devens LLC, and located at 64 Jackson Road, Devens, Massachusetts. The Term Loan contains certain covenants that restrict the Company’s ability to, among other things, incur or assume certain debt, merge or consolidate, materially change the nature of the Company’s business, make certain investments, acquire or dispose of certain assets, make guarantees or grant liens on its assets, make certain loans, advances or investments, declare dividends or make distributions or enter into transactions with affiliates. In addition, there is a covenant that requires the Company to maintain a minimum unrestricted cash balance (the “Minimum Threshold”) in the United States. As a result of the Company’s April 2015 equity offering, the Minimum Threshold was reduced to the lesser of $2.0 million or the aggregate outstanding principal balance of the then outstanding term loans. As of March 31, 2017, the Minimum Threshold was $1.5 million. The events of default under the Term Loan include, but are not limited to, failure to pay amounts due, breaches of covenants, bankruptcy events, cross defaults under other material indebtedness and the occurrence of a material adverse effect and/or change in control. In the case of a continuing event of default, Hercules may, among other remedies, declare due all unpaid principal amounts outstanding and any accrued but unpaid interest and foreclose on all collateral granted to Hercules as security under the Term Loan. Interest expense for the fiscal years ended March 31, 2017, 2016 and 2015, was $0.4 million, $1.0 million and $1.7 million, respectively, which included $0.2 million, $0.4 million and $0.5 million, respectively, of non-cash interest expense related to the amortization of the debt discount and payment of the Note in Company common stock at a discount. Although the Company believes that it is in compliance with the covenants and restrictions under the Term Loan as of March 31, 2017, there can be no assurance that the Company will remain in compliance until the maturity of the Term Loan.

Debt

Senior Secured Term Loans

On November 15, 2013, the Company amended its existing Loan and Security Agreement with Hercules, and entered into a term loan (the “Term Loan B”), borrowing $10.0 million. After closing fees and expenses, the net proceeds to the Company for the Term Loan B were $9.8 million. The Term Loan B bore an interest rate of 11% plus the percentage, if any, by which the prime rate as reported by the Wall Street Journal exceeds 3.75%. The Company repaid the Term Loan B in equal monthly installments ending on November 1, 2016, when the loan was repaid in full. The Company paid an end of term fee of $0.5 million upon the maturity of the Term Loan B, which had been accrued at inception of the loan with a corresponding amount recorded into the debt discount. In addition, the Company incurred $0.2 million of legal and origination costs at the inception of the loan, which have been recorded as a debt discount.

On December 19, 2014, the Company entered into a second amendment with Hercules (the “Hercules Second Amendment”) and entered into a new term loan, borrowing an additional $1.5 million (the “Term Loan C”). After closing fees and expenses, the net proceeds to the Company for the Term Loan C were $1.4 million. The Term Loan C is also referred to as the “Term Loan”. The Term Loan C also bears the same interest rate as the Term Loan B, which increased to 11.25% effective March 16, 2017. The Company will make interest only payments until maturity on June 1, 2017, when the loan is scheduled to be repaid in its entirety. The maturity date of the Term Loan C was extended from March 1, 2017 to June 1, 2017 due to the Company’s April 2015 equity offering which raised more than $10 million in new capital before December 31, 2015. The Company will pay an end of term fee of approximately $0.1 million upon earlier of maturity or prepayment of the Term Loan C. The Company has accrued the end of term fee and recorded a corresponding amount in the debt discount. The Term Loan C includes a mandatory prepayment feature that allows Hercules the right to use any of the Company's net proceeds from specified asset dispositions greater than $1.0 million in a calendar year to pay off any outstanding accrued interest and principle balances on the Term Loan C. The Company determined the fair value to be de-minimus for this feature. In addition, the Company incurred approximately $0.1 million of legal and origination costs in the three months ended December 31, 2014, which have been recorded as a debt discount.

Hercules received warrants to purchase 13,927 shares of common stock (the “First Warrant”) and 25,641 shares of common stock (the “Second Warrant”) in conjunction with a prior term loan which has been repaid in full and the Term Loan B. Due to certain adjustment provisions within the warrants, they qualified for liability accounting and the fair value of the warrants $0.4 million and $0.2 million, respectively, was recorded upon issuance to debt discount and a warrant liability. In conjunction with the Hercules Second Amendment, the First Warrant and Second Warrant were canceled and replaced with the issuance of a new warrant (the “Hercules Warrant”) to purchase 58,823 shares of common stock at an exercise price of $11.00 per share, subject to adjustment. The Warrant expires on June 30, 2020. See Note 10, “Warrants and Derivative Liabilities”, for a discussion on the Warrant and the valuation assumptions used.

Under Term Loan B, the total debt discount including the Warrant, end of term fee and legal and origination costs of $1.0 million was amortized into interest expense over the term of the Term Loan B using the effective interest method. During the years ended March 31, 2017 and 2016, the Company recorded non-cash interest expense for amortization of the debt discount related to the Term Loan B of less than $0.1 million and $0.2 million, respectively. Under Term Loan C, the total debt discount, including the Warrant, end of term fee and legal and origination costs of $0.3 million is being amortized into interest expense over the term of the Term Loan C using the effective interest method. During each of the fiscal years ended March 31, 2017 and 2016, the Company recorded non-cash interest expense for amortization of the debt discount related to the Term Loan C of $0.1 million.

The Term Loan is secured by substantially all of the Company’s existing and future assets, including a mortgage on real property owned by the Company’s wholly-owned subsidiary, ASC Devens LLC, and located at 64 Jackson Road, Devens, Massachusetts. The Term Loan contains certain covenants that restrict the Company’s ability to, among other things, incur or assume certain debt, merge or consolidate, materially change the nature of the Company’s business, make certain investments, acquire or dispose of certain assets, make guarantees or grant liens on its assets, make certain loans, advances or investments, declare dividends or make distributions or enter into transactions with affiliates. In addition, there is a covenant that requires the Company to maintain a minimum unrestricted cash balance (the “Minimum Threshold”) in the United States. As a result of the Company’s April 2015 equity offering, the Minimum Threshold was reduced to the lesser of $2.0 million or the aggregate outstanding principal balance of the then outstanding term loans. As of March 31, 2017, the Minimum Threshold was $1.5 million. The events of default under the Term Loan include, but are not limited to, failure to pay amounts due, breaches of covenants, bankruptcy events, cross defaults under other material indebtedness and the occurrence of a material adverse effect and/or change in control. In the case of a continuing event of default, Hercules may, among other remedies, declare due all unpaid principal amounts outstanding and any accrued but unpaid interest and foreclose on all collateral granted to Hercules as security under the Term Loan.

Interest expense for the fiscal years ended March 31, 2017, 2016 and 2015, was $0.4 million, $1.0 million and $1.7 million, respectively, which included $0.2 million, $0.4 million and $0.5 million, respectively, of non-cash interest expense related to the amortization of the debt discount and payment of the Note in Company common stock at a discount.

Although the Company believes that it is in compliance with the covenants and restrictions under the Term Loan as of March 31, 2017, there can be no assurance that the Company will remain in compliance until the maturity of the Term Loan.