Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Additional Information (Detail)

v2.4.1.9
Stock-Based Compensation - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
6 Months Ended
Mar. 28, 2015
Mar. 29, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Tax benefit associated with share-based compensation expense $ 1.4us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense $ 1.7us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Selling, General and Administrative Expenses [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation expense $ 3.7us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_IncomeStatementLocationAxis
= us-gaap_SellingGeneralAndAdministrativeExpensesMember
$ 4.6us-gaap_AllocatedShareBasedCompensationExpense
/ us-gaap_IncomeStatementLocationAxis
= us-gaap_SellingGeneralAndAdministrativeExpensesMember