v2.4.0.6
Weighted Average Black Scholes Fair Value Assumptions (Detail)
6 Months Ended
Jun. 16, 2012
Jun. 11, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected life 6 years 6 years
Risk free interest rate 1.30% 2.60%
Expected volatility 17.00% [1] 16.00% [1]
Expected dividend yield 3.00% 2.90%
[1] Reflects movements in our stock price over the most recent historical period equivalent to the expected life.