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Weighted Average Assumptions used to Estimate Fair Value of Stock Options (Detail) - Times
12 Months Ended
Dec. 26, 2015
Dec. 27, 2014
Dec. 28, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected volatility 34.20% 34.30% 33.90%
Risk-free interest rate 2.16% 2.83% 1.85%
Expected dividends 0.00% 0.00% 0.00%
Exercise factor 3.0 3.4 2.8
Discount for post-vesting restrictions 0.00% 0.00% 0.00%