b'KOSMOS ENERGY LTD.Notes to Consolidated Financial Statements (Continued)8. DebtDecember 31,2018 2017(In thousands)Outstanding debt principal balances:Facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $1,325,000 $ 800,000Corporate Revolver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325,000 Senior Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525,000 525,000Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,175,000 1,325,000Unamortized deferred financing costs and discounts(1). . . . (54,453) (42,203)Long-term debt, net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $2,120,547 $1,282,797(1) Includes $40.5 million and $23.6 million of unamortized deferred financing costs relatedto the Facility and $14.0 million and $18.6 million of unamortized deferred financing costsand discounts related to the Senior Notes as of December 31, 2018 and December 31,2017, respectively.FacilityIn 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 billionbeing available if the existing financial institutions increase their commitments or if commitments fromnew financial institutions are added. In November 2018, the Company exercised its option with existingfinancial institutions to provide the Company with an additional commitment of $100 million in theaggregate under the Facility. The borrowing base calculation includes value related to the Jubilee, TEN,Ceiba and Okume fields. The Facility supports our oil and gas exploration, appraisal and developmentprograms and corporate activities. As part of the debt refinancing in February 2018, the repayment ofborrowings under the existing facility attributable to financial institutions that did not participate in theamended Facility was accounted for as an extinguishment of debt, and $4.1 million of existingunamortized debt issuance costs and deferred interest attributable to those participants was expensed ininterest and other financing costs, net. As of December 31, 2018, we have $40.5 million of unamortizedissuance costs related to the Facility, which will be amortized over the remaining term of the Facility. InDecember 2018, the Company entered into letter agreements with existing financial institutions, whichprovided the Company with an additional commitment of $100 million in the aggregate under theFacility effective January 31, 2019. This took the total commitments to $1.7 billion as of January 31,2019.As of December 31, 2018, borrowings under the Facility totaled $1,325.0 million and the undrawnavailability under the Facility was $375.0 million, which includes the additional commitments asreferenced above. Interest is the aggregate of the applicable margin (3.25% to 4.50%, depending on thelength of time that has passed from the date the Facility was entered into) and LIBOR. Interest ispayable on the last day of each interest period (and, if the interest period is longer than six months, onthe dates falling at six-month intervals after the first day of the interest period). We pay commitmentfees on the undrawn and unavailable portion of the total commitments, if any. As part of theamendment and restatement process in February 2018, commitment fees were lowered from 40% to30% per annum of the then-applicable respective margin when a commitment is available for utilization128'