Employee Benefits - Components of Plan Benefit Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 03, 2015	Sep. 27, 2014	Oct. 03, 2015	Sep. 27, 2014
Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 28	$ 27	$ 84	$ 80
Interest cost	50	56	156	169
Expected return on plan assets	(100)	(104)	(300)	(313)
Amortization of unrecognized prior service cost (credit)	4	3	10	10
Total plan benefit (income) expense	(18)	(18)	(50)	(54)
Other Nonpension Postretirement
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	7	24	21
Interest cost	11	13	36	40
Expected return on plan assets	(25)	(24)	(75)	(73)
Amortization of unrecognized prior service cost (credit)	(2)	(1)	(3)	(2)
Recognized net loss	0	7	0	7
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments	0	(12)	0	(12)
Total plan benefit (income) expense	(9)	(10)	(18)	(19)
Postemployment
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	5	6
Interest cost	1	1	3	3
Recognized net loss	1	1	3	3
Total plan benefit (income) expense	$ 4	$ 4	$ 11	$ 12