Long-term Financing and Sales of Receivables - Sales Receivables (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016	Dec. 31, 2016
Receivables [Abstract]
Accounts receivable sales proceeds	$ 61	$ 5	$ 80	$ 7
Long-term receivables sales proceeds	22	70	68	134
Total proceeds from receivable sales	83	$ 75	148	$ 141
Servicing obligations for long-term receivables	$ 775		$ 775		$ 774