v2.4.0.8
Share-Based Compensation - Range of Assumptions Used and Resulting Weighted-Average Fair Value of Options Granted at Date of Grant (Detail) (USD $)
3 Months Ended 6 Months Ended
Jun. 29, 2013
Jun. 30, 2012
Jun. 29, 2013
Jun. 30, 2012
Range of assumptions used and resulting weighted-average fair value of options granted at the date of grant        
Risk-free interest rate, minimum 0.70% 0.80% 0.70% 0.80%
Risk-free interest rate, maximum 1.60% 1.30% 1.60% 1.30%
Expected term, years 5 years 6 months 5 years 6 months 5 years 6 months 5 years 6 months
Estimated volatility, minimum 36.20% 37.30% 36.20% 37.30%
Estimated volatility, maximum 37.70% 38.30% 39.60% 42.60%
Expected dividends 0.00% 0.00% 0.00% 0.00%
Weighted-average fair value of options granted $ 7.61 $ 7.66 $ 7.47 $ 7.84