The Company has entered into natural gas transportation and treating agreements through July 2019. Maximum commitments under these transportation agreements as of December 31, 2013 totaled $19.4 million. COMSTOCK RESOURCES, INC. AND SUBSIDIARIES NOTES TO CONSOLIDATED FINANCIAL STATEMENTS — (Continued) Contingencies (6) Stockholders’ Equity (7) Stock-based Compensation Stock Options F-22 The Company amortizes the fair value of stock options granted over the vesting period using the straight-line method. During 2011, 2012 and 2013, the Company had $15.0 million, $13.7 million and $12.8 million, respectively, in stock-based compensation expense which is in general and administrative expenses. The excess income tax provisions from tax deductions associated with stock-based compensation recognized in additional paid in capital were $0.6 million, $1.7 million and $2.0 million for the years ended December 31, 2011, 2012 and 2013, respectively. The Company grants restricted shares of common stock, stock options and performance share units to key employees and directors as part of their compensation under the 2009 Long-term Incentive Plan. Future awards of stock options, restricted stock grants or other equity awards under the 2009 Long-term Incentive Plan are available with up to 1,588,053 shares of common stock. On each of May 15, 2013, August 22, 2013 and November 26, 2013, the Board of Directors declared a dividend of 12.5¢ per share on the Company’s common stock to stockholders of record at the close of business on May 31, 2013, September 6, 2013 and December 6, 2013. Dividends in the aggregate amount of $18.0 million were paid during 2013. The Board of Directors also approved an open market share repurchase plan which permits the Company to repurchase up to $100.0 million of its common stock on the open market. The Company made various open market purchases of 631,096 shares at an aggregate cost of $9.2 million during 2013, and all shares purchased by the Company were cancelled. The authorized capital stock of Comstock consists of 75 million shares of common stock, $0.50 par value per share, and 5 million shares of preferred stock, $10.00 par value per share. The preferred stock may be issued in one or more series, and the terms and rights of such stock will be determined by the Board of Directors. There were no shares of preferred stock outstanding at December 31, 2012 or 2013. From time to time, the Company is involved in certain litigation that arises in the normal course of its operations. The Company records a loss contingency for these matters when it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. The Company does not believe the resolution of these matters will have a material effect on the Company’s financial position or results of operations and no material amounts are accrued relative to these matters at December 31, 2012 or 2013.