Accounts Receivable and Finance Receivables - Finance receivables categorized based on credit quality indicators (Details) $ in Millions	12 Months Ended
	Dec. 30, 2017 USD ($) item	Dec. 31, 2016 USD ($)
Finance receivables categorized based on the internally assigned credit quality
Number of loan categories based on key credit quality indicators for individual loan | item	3
Performing
Finance receivables categorized based on the internally assigned credit quality
Total finance receivables	$ 733	$ 758
Watchlist
Finance receivables categorized based on the internally assigned credit quality
Total finance receivables	56	101
Nonaccrual
Finance receivables categorized based on the internally assigned credit quality
Total finance receivables	$ 61	$ 87
Nonaccrual as a percentage of finance receivables	7.18%	9.20%
Minimum | Nonaccrual
Finance receivables categorized based on the internally assigned credit quality
Number of months of contractual delinquency to classify accounts as nonaccrual unless such collection is not doubtful	3 months