XML 57 R46.htm IDEA: XBRL DOCUMENT v3.4.0.3
Stock-based compensation (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended
Apr. 02, 2016
Apr. 04, 2015
May. 09, 2012
Stock Options [Member]      
Share Based Compensation Arrangement by Share Based Payment Award [Line Items]      
Number of options granted in period (shares) 0 0  
Recognized stock-based compensation costs $ 10 $ 155  
Recognized stock-based compensation costs, net of tax 6 98  
Pre-tax unrecognized compensation expense $ 23    
Weighted-average remaining period to recognize compensation expense 10 months 21 days    
Restricted Stock Units (RSUs) [Member]      
Share Based Compensation Arrangement by Share Based Payment Award [Line Items]      
Recognized stock-based compensation costs $ 9,049 8,281  
Recognized stock-based compensation costs, net of tax 5,491 $ 5,246  
Pre-tax unrecognized compensation expense $ 45,129    
Number of restricted stock units granted (shares) 182,000 158,000  
Weighted-average grant-date fair value (in usd per share) $ 184.88 $ 182.99  
Recognized expense over a weighted-average period (years) 2 years 3 months 11 days    
2012 Long-term Incentive Plan [Member]      
Share Based Compensation Arrangement by Share Based Payment Award [Line Items]      
Expiration year of 2012 Plan Dec. 31, 2022    
2012 Long-term Incentive Plan [Member] | Stock Options [Member]      
Share Based Compensation Arrangement by Share Based Payment Award [Line Items]      
Option awards contractual term (years) 10 years    
2012 Long-term Incentive Plan [Member] | Maximum [Member]      
Share Based Compensation Arrangement by Share Based Payment Award [Line Items]      
Amount of common stock reserved for issuance (shares)     3,200,000
2012 Long-term Incentive Plan [Member] | Maximum [Member] | Stock Options [Member]      
Share Based Compensation Arrangement by Share Based Payment Award [Line Items]      
Vesting period (years) 5 years    
2012 Long-term Incentive Plan [Member] | Maximum [Member] | Restricted Stock Units (RSUs) [Member]      
Share Based Compensation Arrangement by Share Based Payment Award [Line Items]      
Vesting period (years) 5 years    
2012 Long-term Incentive Plan [Member] | Minimum [Member] | Stock Options [Member]      
Share Based Compensation Arrangement by Share Based Payment Award [Line Items]      
Vesting period (years) 3 years    
2012 Long-term Incentive Plan [Member] | Minimum [Member] | Restricted Stock Units (RSUs) [Member]      
Share Based Compensation Arrangement by Share Based Payment Award [Line Items]      
Vesting period (years) 3 years