Long-Term Debt	9 Months Ended
Sep. 30, 2015
Debt Disclosure [Abstract]
Long-Term Debt	6. Long-Term Debt In December 2014, we entered into a Loan and Security Agreement (“Loan Agreement”) with Hercules Technology Growth Capital, Inc. (“Hercules”) under which we could borrow up to $40.0 million in two tranches and for which we paid a $400,000 facility charge to Hercules. We drew down the first tranche of $10.0 million upon closing of the transaction on December 23, 2014. The second tranche, of $30.0 million, was available to be drawn at our option any time prior to September 30, 2015, but only if we achieved certain milestones relating to the ongoing HEPLISAV–B Phase 3 study (“Milestone A”). Milestone A was achieved in July 2015 as the Data and Safety Monitoring Board (“DSMB”) completed its third prespecified review and recommended that the study continue unchanged; however, no additional amounts were drawn down under the terms of the Loan Agreement. In September 2015, we repaid all outstanding amounts under the Loan Agreement, at which time our obligations under the Loan Agreement terminated and Hercules released its security interests in all collateral under the Loan Agreement. We paid to Hercules $11.0 million, which consisted of $10.0 million outstanding principal, accrued but unpaid interest of $38 thousand, end of term fee of $0.8 million and prepayment charges of $0.2 million. We recognized the repayment to be a substantial modification to the debt instrument and applied debt extinguishment accounting to record a one-time loss on extinguishment of debt in the amount of $1.7 million. The interest rate in the Loan Agreement was calculated at a rate equal to the greater of either: (i) 9.75% plus the prime rate as reported from time to time in The Wall Street Journal minus 5.25%, and (ii) 9.75%. Monthly payments made under the Loan Agreement between December 2014 and the date of repayment were interest only.

6. Long-Term Debt

In December 2014, we entered into a Loan and Security Agreement (“Loan Agreement”) with Hercules Technology Growth Capital, Inc. (“Hercules”) under which we could borrow up to $40.0 million in two tranches and for which we paid a $400,000 facility charge to Hercules.

We drew down the first tranche of $10.0 million upon closing of the transaction on December 23, 2014. The second tranche, of $30.0 million, was available to be drawn at our option any time prior to September 30, 2015, but only if we achieved certain milestones relating to the ongoing HEPLISAV–B Phase 3 study (“Milestone A”). Milestone A was achieved in July 2015 as the Data and Safety Monitoring Board (“DSMB”) completed its third prespecified review and recommended that the study continue unchanged; however, no additional amounts were drawn down under the terms of the Loan Agreement.

In September 2015, we repaid all outstanding amounts under the Loan Agreement, at which time our obligations under the Loan Agreement terminated and Hercules released its security interests in all collateral under the Loan Agreement. We paid to Hercules $11.0 million, which consisted of $10.0 million outstanding principal, accrued but unpaid interest of $38 thousand, end of term fee of $0.8 million and prepayment charges of $0.2 million. We recognized the repayment to be a substantial modification to the debt instrument and applied debt extinguishment accounting to record a one-time loss on extinguishment of debt in the amount of $1.7 million.

The interest rate in the Loan Agreement was calculated at a rate equal to the greater of either: (i) 9.75% plus the prime rate as reported from time to time in The Wall Street Journal minus 5.25%, and (ii) 9.75%. Monthly payments made under the Loan Agreement between December 2014 and the date of repayment were interest only.