KOSMOS ENERGY LTD. Notes to Consolidated Financial Statements (Continued) 8. Debt December 31, 2017 2016 (In thousands) Outstanding debt principal balances: Facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 800,000 $ 850,000 Senior Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525,000 525,000 Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,325,000 1,375,000 Unamortized deferred financing costs and discounts(1) . . . . (42,203) (53,126) Long-term debt, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $1,282,797 $1,321,874 (1) Includes $23.6 million and $30.3 million of unamortized deferred financing costs related to the Facility and $18.6 million and $22.8 million of unamortized deferred financing costs and discounts related to the Senior Notes as of December 31, 2017 and December 31, 2016, respectively. Facility In March 2017, following the lender’s semi-annual redetermination, the available borrowing base under our Facility was $1.3 billion (effective April 1, 2017). In August 2017, following the lender’s waiver of the September 30, 2017 semi-annual redetermination, the available borrowing base under our Facility remained at $1.3 billion. The borrowing base calculation included value related to the Jubilee and TEN fields. As of December 31, 2017, borrowings under the Facility totaled $800.0 million including $200 million drawn for the KTIPI investment, and the undrawn availability under the Facility was $500.8 million. Interest is the aggregate of the applicable margin (3.25% to 4.50%, depending on the length of time that has passed from the date the Facility was entered into) and LIBOR. Interest is payable on the last day of each interest period (and, if the interest period is longer than six months, on the dates falling at six-month intervals after the first day of the interest period). We pay commitment fees on the undrawn and unavailable portion of the total commitments, if any. Commitment fees were equal to 40% per annum of the then-applicable respective margin when a commitment is available for utilization and, equal to 20% per annum of the then-applicable respective margin when a commitment is not available for utilization. We recognize interest expense in accordance with ASC 835—Interest, which requires interest expense to be recognized using the effective interest method. We determined the effective interest rate based on the estimated level of borrowings under the Facility. In February 2018, the Company amended and restated the Facility with a total commitment of $1.5 billion from a number of financial institutions with additional commitments up to $0.5 billion being available if the existing financial institutions increase their commitments or if commitments from new financial institutions are added. The Facility supports our oil and gas exploration, appraisal and development programs and corporate activities. As part of the debt refinancing in February 2018, the repayment of borrowings under the existing facility attributable to financial institutions that did not participate in the amended Facility was accounted for as an extinguishment of debt, and $5.7 million of existing unamortized debt issuance costs attributable to those participants were expensed in the first quarter of 2018. As of December 31, 2017, we have $23.6 million of unamortized issuance costs related 128