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Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2017
Sep. 24, 2016
Sep. 30, 2017
Sep. 24, 2016
Dec. 31, 2017
Dec. 31, 2016
Income Taxes [Line Items]            
Effective tax rate 2.00% (267.00%) 24.00% (51.00%)    
Non-cash income tax benefit     $ 36 $ (235)    
U.S. Federal and State            
Income Taxes [Line Items]            
Estimated valuation allowance, determined to be reduced           $ 400
Non-cash income tax benefit $ 37 $ 240        
U.S. Federal and State | Scenario, Forecast            
Income Taxes [Line Items]            
Estimated valuation allowance, determined to be reduced         $ 40