XML 61 R48.htm IDEA: XBRL DOCUMENT v3.8.0.1
Employee Stock Plans - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended
Dec. 29, 2017
Dec. 30, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Share-based compensation $ 3,998 $ 4,171
Shares issued under share-based compensation plans 27,693 237,547
Restricted Stock Units    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Granted 33,600 36,700
Weighted Average Grant Date Fair Value $ 91.79 $ 76.70
Performance Share Plan Shares    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Granted 33,700 42,100
Performance period 3 years  
Performance Share Plan Shares | Minimum    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Percentage of the target number of shares paid out 0.00%  
Performance Share Plan Shares | Maximum    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Percentage of the target number of shares paid out 300.00%  
Employee Share-save Scheme    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Discount rate of market value on purchase date 5.00%  
The term of options, years 3 years  
Number of options granted 0 0
Equity Incentive Plan    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Number of options granted 197,700 231,100
Weighted-average grant date fair value of options granted $ 31.20 $ 32.55
Employee Stock Purchase Plan    
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]    
Discount rate of market value on purchase date 5.00%