Employee Benefits - Components of Plan Benefit Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 01, 2017	Apr. 02, 2016
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 25	$ 24
Interest cost	41	44
Expected return on plan assets	(90)	(89)
Amortization of unrecognized prior service cost (credit)	2	3
Recognized net (gain) loss	3	0
Curtailment loss	1	0
Total plan benefit (income) expense	(18)	(18)
Other Nonpension Postretirement
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	5
Interest cost	9	10
Expected return on plan assets	(24)	(22)
Amortization of unrecognized prior service cost (credit)	(2)	(3)
Recognized net (gain) loss	(29)	0
Curtailment loss	3	0
Total plan benefit (income) expense	(38)	(10)
Postemployment
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2
Interest cost	1	1
Recognized net (gain) loss	1	1
Total plan benefit (income) expense	$ 3	$ 4