Annual report pursuant to Section 13 and 15(d)

Stock Incentive Plans (Details)

v3.3.1.900
Stock Incentive Plans (Details)
$ / shares in Units, $ in Thousands
 12 Months Ended 24 Months Ended
Dec. 27, 2015
USD ($)
stock-based_compensation_plan
$ / shares
shares
Dec. 28, 2014
USD ($)
$ / shares
shares
Dec. 29, 2013
USD ($)
$ / shares
Dec. 25, 2011
Dec. 28, 2014
$ / shares
shares
Dec. 27, 2015
USD ($)
shares
Dec. 28, 2014
USD ($)
shares
Share-based compensation plan disclosures              
Expiration from date of grant 10 years            
Total stock-based compensation cost | $ $ 4,700 $ 4,200 $ 3,800        
Income tax benefits from stock-based compensation cost | $ $ 2,000 $ 1,700 $ 1,500        
Total unrecognized compensation cost | $           $ 3,400  
Number of common shares issued per RSU 1            
Stock Options              
Share-based compensation plan disclosures              
Shares outstanding 462,000 462,000     462,000 395,000 462,000
Weighted average remaining vesting period 1 year 2 months 12 days            
Shares              
Outstanding, beginning of period (in shares) 462,000            
Granted (in shares) 72,000            
Forfeited (in shares) (44,000)            
Exercised (in shares) (95,000)            
Outstanding, end of period (in shares) 395,000 462,000     462,000    
Weighted Average Exercise Price              
Outstanding, beginning of period (in dollars per share) | $ / shares $ 38.83            
Granted (in dollars per share) | $ / shares 81.84            
Forfeited (in dollars per share) | $ / shares 49.35            
Exercised (in dollars per share) | $ / shares 36.49            
Outstanding, end of period (in dollars per share) | $ / shares $ 46.04 $ 38.83     $ 38.83    
Weighted average assumptions used in estimation of fair value of options              
Risk-free interest rate (as a percent) 1.40% 1.70% 0.70%        
Expected years until exercise 4 years 9 months 18 days 5 years 8 months 12 days 4 years 2 months        
Expected stock volatility (as a percent) 40.60% 44.60% 44.40%        
Dividend yield (as a percent) 0.00% 0.00% 0.00%        
Weighted average Black-Scholes fair value per share at date of grant (in dollars per share) | $ / shares $ 29.71 $ 30.70 $ 15.19        
Total intrinsic value of options exercised | $ $ 4,414 $ 3,954 $ 8,263        
Restricted Stock              
Share-based compensation plan disclosures              
Weighted average remaining vesting period 1 year 1 month 6 days            
Restricted Stock | Board of Directors              
Share-based compensation plan disclosures              
Vesting period 1 year       3 years    
2007 Stock Plan              
Share-based compensation plan disclosures              
Maximum number of shares of the company's common stock that may be issued or transferred           2,074,600  
Period following the change in control during which termination of an individual without cause will trigger vesting of award 2 years            
Shares outstanding 391,923         391,923  
Vested (in shares)           227,300  
Shares              
Outstanding, end of period (in shares) 391,923            
2007 Stock Plan | Time Based RSUs              
Share-based compensation plan disclosures              
Vesting period 4 years            
Shares              
Outstanding, beginning of period (in shares) 101,000            
Awarded (in shares) 33,000            
Forfeited (in shares) (13,000)            
Vested (in shares) (46,000)            
Outstanding, end of period (in shares) 75,000 101,000     101,000    
Weighted Average Grant-Date Fair Value (per share)              
Outstanding, beginning of period (in dollars per share) | $ / shares $ 49.78            
Granted (in dollars per share) | $ / shares 82.52            
Cancelled (in dollars per share) | $ / shares 53.79            
Vested (in dollars per share) | $ / shares 42.82            
Outstanding, end of period (in dollars per share) | $ / shares $ 67.74 $ 49.78     $ 49.78    
Other stock-based compensation plans              
Share-based compensation plan disclosures              
Expiration term 10 years            
Shares outstanding 74,530         74,530  
Number of stock-based compensation plans | stock-based_compensation_plan 4            
Shares              
Outstanding, end of period (in shares) 74,530            
Other stock-based compensation plans | Minimum              
Share-based compensation plan disclosures              
Vesting period 1 year            
Other stock-based compensation plans | Maximum              
Share-based compensation plan disclosures              
Vesting period 4 years            
Long-Term Cash Incentive Plan | Deferred compensation, excluding share-based payments and retirement benefits              
Additional disclosure              
Performance and vesting period       3 years      
Compensation expense | $ $ 3,300 $ 800 $ 4,200        
Payments of performance stock awards | $ $ 1,800 $ 2,400          
Accrued payroll liabilities and payroll-related liabilities | Long-Term Cash Incentive Plan | Deferred compensation, excluding share-based payments and retirement benefits              
Additional disclosure              
Long-term cash incentive plan liability | $           $ 6,300 $ 4,800