Stockholders' Equity

12 Months Ended

Dec. 31, 2017

Stockholders' Equity Note [Abstract]

Stockholders' Equity

Note 7. Stockholders’ Equity

401(k) Plan

We offer a 401(k) plan to which employees may contribute earnings subject to IRS limitations.  We match 100% of an employee’s contribution, up to 6% of compensation, as defined by the plan, which is vested immediately.  During 2017, 2016 and 2015, our matching contributions to the 401(k) plan were approximately $7.1 million, $7.7 million and $10.1 million, respectively.

2017 Retirement of Treasury Stock

During the year ended December 31, 2017, we retired 5.0 million shares of existing treasury stock, with a carrying value of $46.6 million, acquired principally through the delivery by our employees of shares to satisfy tax withholding requirements related to the vesting of restricted shares, as well as shares acquired through our stock repurchase program. These retired shares are now included in the pool of authorized but unissued shares. Our accounting policy upon the retirement of treasury stock is to deduct its par value from common stock and reduce additional paid-in capital by the excess amount of treasury stock retired.