oil and natural gas prices. The determination of the borrowing base is at the sole discretion of the administrative agent and the bank group. Borrowings under the bank credit facility bear interest, based on the utilization of the borrowing base, at our option at either (1) LIBOR plus 1.5% to 2.5% or (2) the base rate (which is the higher of the administrative agent’s prime rate, the federal funds rate plus 0.5% or 30 day LIBOR plus 1.0%) plus 0.5% to 1.5%. A commitment fee of 0.375% to 0.5%, based on the utilization of the borrowing base, is payable annually on the unused borrowing base. The bank credit facility contains covenants that, among other things, restrict the payment of cash dividends and repurchases of common stock in excess of $120.0 million per year, limit the amount of consolidated debt that we may incur and limit our ability to make certain loans and investments. The only financial covenants are the maintenance of a leverage ratio and the maintenance of an interest coverage ratio. We were in compliance with these covenants as of December 31, 2013. At December 31, 2012 we had $300.0 million in principal amount of 8 $^{3}$⁄ 8% senior notes outstanding with a maturity date of October 15, 2017 (the “2017 Notes”). In June 2013, we repurchased $2.2 million in principal amount of the 2017 Notes at 103.3% of the par value and on September 13, 2013, we called all of the remaining 2017 Notes at the call price of 104.2% of par value for redemption on October 15, 2013. The redemption amount of $310.2 million was funded with cash on hand of $210.2 million and borrowings under our bank credit facility. As a result of this redemption, we recognized a loss on early extinguishment of debt, before income taxes, of approximately $17.9 million comprised of the premium paid for the redemption, the costs incurred related to the redemption and the write-off of unamortized debt issuance costs, including original issuance discount. We have $300.0 million of 7 $^{3}$⁄ 4% senior notes (the “2019 Notes”) outstanding which are due on April 1, 2019 and bear interest which is payable semi-annually on each April 1 and October 1. We also have $300.0 million of 9 $^{1}$⁄ 2% senior notes (the “2020 Notes”) which are due on June 15, 2020 and bear interest which is payable semi-annually on each June 15 and December 15. The 2019 and 2020 Notes are unsecured obligations which are guaranteed by all of our material subsidiaries. Such subsidiary guarantors are 100% owned and all of the guarantees are full and unconditional and joint and several obligations. As of December 31, 2013, we had no material assets or operations which are independent of our subsidiaries. There are no restrictions on our ability to obtain funds from our subsidiaries through dividends or loans. On January 1, 2011, we had $172.0 million in principal amount of 6 $^{7}$⁄ 8% senior notes outstanding due in 2012 (the “2012 Notes”). We redeemed all of the 2012 Notes in 2011 for $172.4 million. The early extinguishment of the 2012 Notes resulted in a loss of $1.1 million. This loss is comprised of the premium paid for the redemption of the 2012 Notes, the costs incurred related to the tender offer, and the write-off of unamortized debt issuance costs related to the 2012 Notes. We believe that our cash flow from operations and available borrowings under our bank credit facility will be sufficient to fund our operations and future growth as contemplated under our current business plan. However, if our plans or assumptions change or if our assumptions prove to be inaccurate, we may be required to seek additional capital. We cannot provide any assurance that we will be able to obtain such capital, or if such capital is available, that we will be able to obtain it on acceptable terms. 54