Pensions and Other Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016
Retirement Plans
Components of net periodic benefit cost
Service cost	$ 1,080	$ 949	$ 1,037
Interest cost	927	927	988
Expected return on plan assets	(2,041)	(1,962)	(1,809)
Amortization of prior service cost (credit)	2	1	2
Recognized actuarial losses	609	496	745
Curtailments and settlements	17	11	8
Net periodic benefit cost	594	422	971
Other Benefit Plans
Components of net periodic benefit cost
Service cost	247	224	257
Interest cost	159	158	186
Expected return on plan assets	(6)	(6)	(7)
Amortization of prior service cost (credit)	(30)	(34)	(33)
Recognized actuarial losses	138	135	201
Curtailments and settlements	0	0	0
Net periodic benefit cost	$ 508	$ 477	$ 604