Pensions and Other Postretirement Benefits - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 02, 2016	Sep. 27, 2015	Oct. 02, 2016	Sep. 27, 2015
Retirement Plans
Components of net periodic benefit cost
Service cost	$ 224	$ 247	$ 676	$ 744
Interest cost	232	246	698	743
Expected return on plan assets	(490)	(451)	(1,475)	(1,361)
Amortization of prior service cost/(credit)	2	0	2	1
Recognized actuarial losses	123	186	371	560
Curtailments and settlements	6	0	11	4
Net periodic benefit cost	97	228	283	691
Other Benefit Plans
Components of net periodic benefit cost
Service cost	56	64	166	193
Interest cost	39	46	118	139
Expected return on plan assets	(1)	(2)	(4)	(5)
Amortization of prior service cost/(credit)	(9)	(8)	(25)	(25)
Recognized actuarial losses	33	50	101	150
Curtailments and settlements	0	0	0	0
Net periodic benefit cost	$ 118	$ 150	$ 356	$ 452