Employee Benefits - Components of Plan Benefit Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 02, 2016	Apr. 04, 2015
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 24	$ 28
Interest cost	44	53
Expected return on plan assets	(89)	(100)
Amortization of unrecognized prior service cost (credit)	3	3
Total plan benefit (income) expense	(18)	(16)
Other Nonpension Postretirement
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	8
Interest cost	10	12
Expected return on plan assets	(22)	(25)
Amortization of unrecognized prior service cost (credit)	(3)	0
Total plan benefit (income) expense	(10)	(5)
Postemployment
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2
Interest cost	1	1
Recognized net loss	1	1
Total plan benefit (income) expense	$ 4	$ 4