XML 49 R35.htm IDEA: XBRL DOCUMENT v3.6.0.2
Share Based Compensation (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2016
Dec. 26, 2015
Dec. 27, 2014
Dec. 28, 2013
Share-based Compensation Arrangement by Share-based Payment Award          
Vesting Term, Minimum   1 year      
Vesting Term   4 years      
Number of shares available for future equity awards (in shares) 3,800,000 3,800,000      
Share-based compensation   $ 23,554 $ 19,420 $ 16,173  
Blended volatility weighting percentage for historical   75.00%      
Blended volatility weighting percentage for implied   25.00%      
Payments Related to Tax Withholding for Share-based Compensation   $ 843 $ 2,997 $ 4,766  
Stock options, additional disclosures          
Weighted average fair value, Granted (in dollars per share)   $ 19.27 $ 19.53 $ 15.36  
Weighted average remaining contractual term, Outstanding, end of period (in years)   6 years 11 months 5 days 7 years 1 month 5 days 7 years 2 months 6 days 7 years 1 month 6 days
Weighted average remaining contractual rerm, Exercisable at end of period (in years)   5 years 6 months 5 days      
Aggregate intrinsic value, Outstanding, beginning of period   $ 119,050 $ 146,967 $ 193,123  
Aggregate intrinsic value, Outstanding, end of period $ 59,601 59,601 $ 119,050 $ 146,967 $ 193,123
Aggregate intrinsic value, Exercisable at end of period 56,198 $ 56,198      
Other information relative to restricted unit activity          
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Description and Terms   0 0 0  
Restricted Stock Units (RSUs)          
Share-based Compensation Arrangement by Share-based Payment Award          
Total unrecognized compensation $ 5,400 $ 5,400      
Remaining weighted average expense recognition period (in years) 1 year 7 months 17 days        
Shares issued as a result of vested restricted stock units (in shares)   48,267 72,206 134,964  
Shares withheld to satisfy tax obligations (in shares)   10,236 35,342 77,192  
Payments Related to Tax Withholding for Share-based Compensation   $ 843 $ 2,997 $ 4,766  
Restricted stock units          
Restricted, beginning of period (in shares)   219,617 277,347 413,158  
Granted (in shares)   59,586 56,052 97,817  
Exercised (in shares)   (58,503) (107,548) (212,156)  
Forfeited (in shares)   (26,669) (6,234) (21,472)  
Restricted, end of period (in shares) 194,031 194,031 219,617 277,347 413,158
Restricted stock units, additional disclosures          
Weighted average grant date fair value, Restricted, beginning of period (in dollars per share)   $ 60.99 $ 42.64 $ 26.12  
Weighted average grant date fair value, Granted (in dollars per share)   83.22 84.86 70.09  
Weighted average grant date fair value, Exercised (in dollars per share)   52.51 25.97 21.91  
Weighted average grant date fair value, Forfeited (in dollars per share)   76.51 63.57 54.54  
Weighted average grant date fair value, Restricted, end of period (in dollars per share) $ 68.04 $ 68.04 $ 60.99 $ 42.64 $ 26.12
Other information relative to restricted unit activity          
Total grant date fair value of restricted units vested and exercised   $ 3,072 $ 2,793 $ 4,647  
Total intrinsic value of restricted units vested and exercised   5,104 $ 9,139 $ 13,205  
Employee Stock Option          
Share-based Compensation Arrangement by Share-based Payment Award          
Total unrecognized compensation $ 21,300 $ 21,300      
Remaining weighted average expense recognition period (in years) 1 year 8 months        
Key assumptions in fair value determination          
Expected price volatility, minimum (in hundredths)   25.50% 27.30% 27.30%  
Expected price volatility, maximum (in hundredths)   27.90% 28.80% 28.80%  
Risk-free interest rate, minimum (in hundredths)   0.90% 1.20% 1.20%  
Risk-free interest rate, maximum (in hundredths)   1.30% 1.50% 1.50%  
Forfeiture rate, minimum (in hundredths)   7.10% 6.90% 6.90%  
Forfeiture rate, maximum (in hundredths)   7.10% 6.90% 6.90%  
Dividend yield, minimum (in hundredths)   0.90% 1.00% 1.00%  
Dividend yield, maximum (in hundredths)   0.90% 1.00% 1.00%  
Stock option expiration date (in years)   10 10 10  
Stock option activity          
Outstanding, beginning of period (in shares)   3,861,506 4,083,426 4,309,048  
Granted (in shares)   1,150,941 1,080,490 1,167,060  
Exercised (in shares)   (851,118) (1,116,828) (1,179,175)  
Canceled (in shares)   (187,582) (185,582) (213,507)  
Outstanding, end of period (in shares) 3,973,747 3,973,747 3,861,506 4,083,426 4,309,048
Exercisable, end of period (in shares) 2,011,529 2,011,529      
Stock options, additional disclosures          
Weighted average exercise price, Outstanding, beginning of period (in dollars per share)   $ 54.95 $ 41.93 $ 30.72  
Weighted average exercise price, Granted (in dollars per share)   86.05 83.70 64.08  
Weighted average exercise price, Exercised (in dollars per share)   42.53 33.11 20.15  
Weighted average exercise price, Cancelled (in dollars per share)   80.01 67.28 57.14  
Weighted average exercise price, Outstanding, end of period (in dollars per share) $ 65.43 65.43 $ 54.95 $ 41.93 $ 30.72
Weighted average exercise price, Exercisable, end of period (in dollars per share) $ 48.98 $ 48.98      
Other information relative to option activity          
Total fair value of stock options vested   $ 15,184 $ 13,207 $ 10,855  
Total intrinsic value of stock options exercised   $ 39,696 $ 60,082 $ 60,656  
Employee Stock Option | Minimum          
Key assumptions in fair value determination          
Weighted average expected lives (in years)   4 years 5 months 4 years 6 months 4 years 6 months  
Employee Stock Option | Maximum          
Key assumptions in fair value determination          
Weighted average expected lives (in years)   4 years 5 months 4 years 6 months 4 years 6 months  
Employee Stock Purchase Plan          
Share-based Compensation Arrangement by Share-based Payment Award          
Share-based compensation   $ 1,100 $ 1,100 $ 1,000  
Discount rate of employee stock purchase plan (in hundredths)   15.00%      
Shares of common stock issued for employee stock purchase plan (in shares)   69,562 68,428 78,670  
Shares of common stock reserved for future issuance under the ESPP (in shares) 12,100,000 12,100,000      
Employee Stock Purchase Plan | Maximum          
Share-based Compensation Arrangement by Share-based Payment Award          
Shares of common stock reserved for future issuance under the ESPP (in shares) 16,000,000 16,000,000