Notes Payable	12 Months Ended
Dec. 31, 2017
Notes Payable
Notes Payable	6. Notes Payable In 2014, we borrowed an aggregate of $7.0 million in connection with a Loan and Security Agreement, as amended (LSA). In July 2017, we paid in full the entire outstanding term loans balance of $3.5 million and accrued interest, with no penalty for prepayment. Through July 2017 and pursuant to the terms of the LSA, we were required to make monthly interest payments for all outstanding borrowings at an interest rate equal to the greater of (a) prime rate plus 3.25% or (b) 6.5% and monthly principal payments of 1/24th of our principal borrowings plus interest. Interest expense related to the term loans was $0.2 million, $0.5 million and $0.5 million for the years ended December 31, 2017, 2016 and 2015, respectively. As of December 31, 2017, we had no accrued interest.

Notes Payable

12 Months Ended

Dec. 31, 2017

6. Notes Payable

In 2014, we borrowed an aggregate of $7.0 million in connection with a Loan and Security Agreement, as amended (LSA). In July 2017, we paid in full the entire outstanding term loans balance of $3.5 million and accrued interest, with no penalty for prepayment. Through July 2017 and pursuant to the terms of the LSA, we were required to make monthly interest payments for all outstanding borrowings at an interest rate equal to the greater of (a) prime rate plus 3.25% or (b) 6.5% and monthly principal payments of 1/24th of our principal borrowings plus interest.

Interest expense related to the term loans was $0.2 million, $0.5 million and $0.5 million for the years ended December 31, 2017, 2016 and 2015, respectively. As of December 31, 2017, we had no accrued interest.