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Stock-Based Compensation - Weighted-Average Assumptions Utilized to Value Stock Options (Detail) - USD ($)
3 Months Ended 6 Months Ended
Apr. 01, 2017
Mar. 26, 2016
Apr. 01, 2017
Mar. 26, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]        
Risk-free interest rate 1.80% 1.60% 1.80% 1.60%
Expected volatility 36.50% 37.80% 36.60% 37.80%
Expected life (in years) 4 years 8 months 8 days 4 years 8 months 8 days 4 years 8 months 8 days 4 years 8 months
Dividend yield $ 0 $ 0 $ 0 $ 0
Weighted average fair value of options granted $ 13.44 $ 11.80 $ 12.28 $ 12.98