Stockholder's Equity | Stockholders' Equity During the nine -month period ended September 25, 2016 , we repurchased 758,894 shares of our common stock for an aggregate purchase price of $105,852 . The repurchased shares were concurrently retired and credited to authorized, but unissued stock. The repurchase of these shares resulted in a decrease in common stock of $6,446 and a decrease in retained earnings of $99,406 for the same period. We have 1.6 million shares of common stock reserved for issuance under our current Equity Incentive Plan (Plan) for our employees, officers, and directors. The Plan had 652,019 shares available for grant as of September 25, 2016 . Stock Options The exercise price for stock options issued under the Plan is to be not less than the fair market value on the date of grant with respect to incentive and nonqualified stock options. Stock options vest in four equal annual installments and have a contractual life of seven years. We issue new shares of common stock upon the exercise of stock options. Option activity for the nine months ended September 25, 2016 is summarized as follows: Number of shares Weighted average exercise price Average remaining contractual life (years) Aggregate intrinsic value Outstanding, December 27, 2015 131,248 $ 113.12 4.0 $ 7,051 Granted 33,996 147.55 Exercised (10,215 ) 71.43 Cancelled (4,612 ) 152.42 Expired (535 ) 147.52 Outstanding, September 25, 2016 149,882 $ 122.44 4.0 $ 5,683 Exercisable, September 25, 2016 76,934 $ 96.14 2.6 $ 4,758 The aggregate intrinsic value in the table above is before applicable income taxes, based on our closing stock price of $155.38 as of the last business day of the nine -month period ended September 25, 2016 , which would have been received by the optionees had all options been exercised and sold on that date. As of September 25, 2016 , total unrecognized stock-based compensation expense related to nonvested stock options was approximately $2,378 , which is expected to be recognized over a weighted average period of approximately 2.5 years . During the nine -month periods ended September 25, 2016 and September 27, 2015 , the total intrinsic value of stock options exercised was $848 and $4,012 , respectively. During the nine -month periods ended September 25, 2016 and September 27, 2015 , the weighted average grant date fair value of options was $47.67 and $59.11 , respectively. No shares vested during either of the nine -month periods ended September 25, 2016 or September 27, 2015 . Restricted Stock Units Restricted stock units are granted annually under the Plan at the discretion of the Compensation Committee of our Board of Directors. We grant restricted stock units subject to three -year cliff vesting and a cumulative three -year earnings target. The number of units that vest at the end of the three-year period is based on performance against the target. These restricted stock units are subject to forfeiture if they have not vested at the end of the three-year period. Stock-based compensation is recognized for the number of units expected to vest at the end of the period and is expensed beginning on the grant date through the end of the performance period. For each grant, restricted stock units meeting the performance criteria will vest as of the end of the third fiscal year in the performance period, subject to a Plan-specified maximum number of shares that may be issued to any individual in any year in settlement of restricted stock units. The distribution of vested restricted stock units as common stock typically occurs in March of the following year. The common stock is issued to participants net of the number of shares needed for the required minimum employee withholding taxes. We issue new shares of common stock upon the disbursement of restricted stock units. Restricted stock units are contingently issuable shares, and the activity for the nine months ended September 25, 2016 was as follows: Number of shares Weighted average grant date fair value Outstanding, December 27, 2015 190,120 $ 161.06 Granted 122,911 147.02 Vested (7,449 ) 122.43 Cancelled (17,579 ) 161.64 Outstanding, September 25, 2016 288,003 $ 156.04 As of September 25, 2016 , the total stock-based compensation expense related to nonvested awards not yet recognized was $7,225 , which is expected to be recognized over a weighted average period of 2.0 years. The weighted average grant date fair value of restricted stock units granted during the nine -month periods ended September 25, 2016 and September 27, 2015 was $147.02 and $180.60 , respectively. During the nine -month periods ended September 25, 2016 and September 27, 2015 , we recognized $862 and $10,214 , respectively, of stock-based compensation expense related to restricted stock units. The nine -month period ended September 25, 2016 included reversals of previously recognized expenses as we reduced our estimate of financial performance. Employee Stock Purchase Plan We have reserved 600,000 shares of common stock for issuance under our Employee Stock Purchase Plan (ESPP). The ESPP is available to substantially all employees subject to employment eligibility requirements. Participants may purchase our common stock at 85% of the beginning or ending closing price, whichever is lower, for each six-month period ending in May and November. During the nine -month periods ended September 25, 2016 , and September 27, 2015 , we issued 12,857 and 8,747 shares of common stock, respectively, under the ESPP. As of September 25, 2016 , we had 172,901 shares available for future issuance under the ESPP. |