Debt Disclosure [Text Block] | C. Debt Obligations Deerfield Facility Agreement On June 2, 2014, the Company entered into a $60 million facility agreement (the “Deerfield Facility Agreement”) with Deerfield Private Design Fund III, LP (“Deerfield”). The first payment to the Company under the terms of the Deerfield Facility Agreement consisted of a term loan of $15 million (the “Term Notes”) and a senior secured loan of $10 million (the “Deerfield Convertible Notes”). As of June 30, 2016, Deerfield is no longer obligated to provide the Company any additional disbursements under the Deerfield Facility Agreement. All loans issued under the Deerfield Facility Agreement bear interest at 9.75% per annum. Deerfield may convert any portion of the outstanding principal and any accrued but unpaid interest on the Deerfield Convertible Notes into shares of the Company’s common stock at an initial conversion price of $5.85 per share. The Company also issued to Deerfield a warrant to purchase 14,423, 076 shares of Series D redeemable convertible preferred stock (“Series D Preferred”) at an exercise price of $0.78 per share, which is exercisable until June 2, 2024 (the “Deerfield Warrant”). Upon completion of the IPO, the Deerfield Warrant automatically converted into a warrant to purchase 1,923,077 shares of the Company’s common stock at an exercise price of $5.85 per share. This warrant qualifies as a participating security under ASC Topic 260, Earnings per Share In addition, the Company issued to Deerfield 1,923,077 shares of Series D Preferred as consideration for the loans provided to the Company under the Deerfield Facility Agreement. Upon completion of the IPO, these shares automatically reclassified into 256,410 shares of the Company’s common stock. The Company recorded the fair value of the shares of Series D Preferred of $1.5 million, to debt issuance costs on the date of issuance. The Company recorded the fair value of the Deerfield Warrant and the embedded Put Option to debt discount on the date of issuance. The debt issuance costs and debt discount are amortized over the term of the related debt and the expense is recorded as interest expense in the statements of operations. The Company must repay one-third of the outstanding principal amount of all debt i ssued under the Deerfield Facility Agreement on the fourth and fifth anniversaries of the Deerfield Facility Agreement. The Company is then obligated to repay the balance of the outstanding principal amount on February 14, 2020. The Company prepaid all outstanding interest and principal on the Term Notes in February 2016. Interest accrued on outs tanding debt under the Deerfield Facility Agreement is due quarterly in arrears. Upon notice to Deerfield, the Company may choose to have one or more of the first eight of such scheduled interest payments added to the outstanding principal amount of the debt issued under the Deerfield Facility Agreement, provided that all such interest was due on July 1, 2016. The Company elected this option on all eight of the scheduled interest payments through June 30, 2016. The accrued interest added to outstanding principal is reflected in the condensed balance sheets as current portion of convertible notes and was paid to Deerfield on July 1, 2016. Second Amendment to Senior Secured Co nvertible Note and Warrant On January 6, 2016, the Company entered into a Second Amendment (the “ Second Amendment”) to the Deerfield Convertible Notes and Deerfield Warrant, by and between the Company and Deerfield. The Second Amendment, among other things, clarified the calculation of an anti-dilution adjustment of the conversion price and exercise price of the Deerfield Convertible Notes and Deerfield Warrant, respectively, in the event that the Company effects a firm commitment underwritten public offering of its securities. Except as modified by the Second Amendment and Third Amendment (as described below), all terms and conditions of the Deerfield Convertible Notes and Deerfield Warrant remain in full force and effect. Issuance of 2021 Notes and Thi rd Amendment to Senior Secured Convertible Note and Warrant On February 9, 2016, the Company issued $86.25 million aggregate principal amount of its 5.50% Senior Convertible Notes due 2021 (the “ 2021 Notes”) to Cowen and Company, LLC and RBC Capital Markets, LLC., as representatives of the several initial purchasers (the “Initial Purchasers”), who subsequently resold the 2021 Notes to qualified institutional buyers (the “Note Offering”) in reliance on the exemption from registration provided by Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). The net proceeds from the Note Offering were approximately $82.8 million, after deducting the Initial Purchasers ’ discount and estimated offering expenses. Concurrent with the Note Offering, the Company used approximately $18.6 million of the net proceeds from the Note Offering to repay in full the Term Notes, plus all accrued but unpaid interest, a make whole interest payment and a prepayment premium on the Term Notes. The 2021 Notes were issued pursuant to an Indenture, dated as of February 9, 2016 (the “Indenture”), between the Company and U.S. Bank National Association, as trustee. Interest on the 2021 Notes will be payable semi-annually in cash in arrears on February 1 and August 1 of each year, beginning on August 1, 2016, at a rate of 5.50% per year. The 2021 Notes mature on February 1, 2021 unless earlier converted or repurchased. The 2021 Notes are not redeemable prior to the maturity date, and no sinking fund is provided for the 2021 Notes. The 2021 Notes are convertible at an initial conversion rate of 58.4454 shares of the Company ’s common stock per $1,000 principal amount of the 2021 Notes, subject to adjustment under the Indenture, which is equal to an initial conversion price of approximately $17.11 per share of common stock. Upon conversion, the 2021 Notes will be settled in shares of the Company’s common stock, together with a cash payment in lieu of delivering any fractional share. The conversion rate will be subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date, the Company will increase the conversion rate for a holder who elects to convert its 2021 Notes in connection with such a corporate event in certain circumstances . If the Company undergoes a “ fundamental change” (as defined in the Indenture), holders may require that the Company repurchase for cash all or any portion of their 2021 Notes at a fundamental change repurchase price equal to 100% of the principal amount of the 2021 Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. In addition, holders who convert their 2021 Notes on or after the date that is one year after the last date of original issuance of the 2021 Notes may also be entitled to receive, under certain circumstances, an interest make-whole payment payable in shares of the Company’s common stock. The Company is bifurcating the fundamental change and make-whole interest payment provisions as embedded derivatives and marking them to fair value each reporting period (Note H). The Indenture includes customary terms and covenants, including certain events of default after which the 2021 Notes may be due and payable immediately. In connection with the Note Offering, on February 3, 2016, the Company entered into a Third Amendment (the “ Third Amendment”) to the Deerfield Facility Agreement, Deerfield Convertible Notes and Deerfield Warrant with Deerfield. The Third Amendment, among other things, eliminated the Company’s ability to require Deerfield to convert the Deerfield Convertible Notes into Company common stock. In addition, pursuant to the Third Amendment, Deerfield consented to the prepayment of the Term Notes and the issuance of the 2021 Notes. Except as modified by the Third Amendment, all terms and conditions of the Deerfield Facility Agreement remain in full force and effect. Line of Credit Th e Company has a $100,000 credit agreement with Wells Fargo Bank, N.A. (the “Second Line of Credit Agreement”). As of June 30, 2016, the Company had $73,000 available under the Second Line of Credit Agreement. During the second quarter of 2016, the Company closed its prior $50,000 credit agreement with Wells Fargo Bank, N.A. Also during the second quarter of 2016, the Company opened a new line of credit with a total borrowing capacity of $1.1 million with City National Bank of Florida (the "Third Line of Credit Agreement") to support several irrevocable letters of credit issued by the bank on behalf of the Company. The line of credit has a maturity date of January 31, 2018. As of June 30, 2016, the Company had no outstanding balance under the line of credit. The Third Line of Credit Agreement is collateralized by a restricted money market account, equal to the total amount of the borrowing capacity under the line of credit, held by the same bank institution. The money market account is reported as restricted cash on the balance sheet. The line of credit contains no financial covenants. The interest rate under the Third Line of Credit Agreement was 2.47% as of June 30, 2016. |