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Stock-Based Awards - Stock-Settled Restricted Stock Units (Details) - Stock-settled Restricted Stock Units [Member] - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
12 Months Ended
Dec. 31, 2017
Dec. 25, 2016
Dec. 27, 2015
Restricted Stock Units (in shares):      
Unvested stock-settled restricted stock units at beginning of period 1,008    
Granted 466    
Vested (505)    
Forfeited (83)    
Unvested stock-settled restricted stock units at end of period 886 1,008  
Unvested stock-settled restricted stock units expected to vest at end of period 840    
Weighted Average Grant-Date Fair Value (in dollars per share):      
Unvested stock-settled restricted stock units at beginning of period $ 14    
Granted 16    
Vested 14    
Forfeited 14    
Unvested stock-settled restricted stock units at end of period 15 $ 14  
Unvested stock-settled restricted stock units expected to vest at end of period $ 15    
Restricted stock units vested, intrinsic value $ 7.9 $ 7.3 $ 5.5
Five-year vesting [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Vesting period 5 years