Retirement Plans - Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Millions	12 Months Ended
	Jan. 02, 2021	Jan. 04, 2020	Dec. 29, 2018
Other changes in plan assets and benefit obligations recognized in OCI
Current year actuarial loss (gain)	$ 144	$ 218	$ 248
Amortization of net actuarial gain (loss)	(184)	(99)	(152)
Amortization of prior service credit (cost)	(6)	(8)	(9)
Cost associated with defined contribution	128	130	125
Pension Benefits
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	106	91	104
Interest cost	293	326	306
Expected return on plan assets	(574)	(556)	(553)
Amortization of prior service cost (credit)	11	14	15
Amortization of net actuarial loss (gain)	185	101	153
Net periodic benefit cost (credit)*	21	(24)	25
Other changes in plan assets and benefit obligations recognized in OCI
Current year actuarial loss (gain)	146	207	270
Current year prior service cost	8	0	20
Amortization of net actuarial gain (loss)	(185)	(101)	(153)
Amortization of prior service credit (cost)	(11)	(14)	(15)
Business disposition	0	0	(7)
Total recognized in OCI, before taxes	(42)	92	115
Total recognized in net periodic benefit cost (credit) and OCI	(21)	68	140
Pension Benefits | United States
Other changes in plan assets and benefit obligations recognized in OCI
Cost associated with defined contribution	11	13	13
Postretirement Benefits Other than Pensions
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2	3	3
Interest cost	8	10	10
Expected return on plan assets	0	0	0
Amortization of prior service cost (credit)	(5)	(6)	(6)
Amortization of net actuarial loss (gain)	(1)	(2)	(1)
Net periodic benefit cost (credit)*	4	5	6
Other changes in plan assets and benefit obligations recognized in OCI
Current year actuarial loss (gain)	(2)	11	(22)
Current year prior service cost	0	0	0
Amortization of net actuarial gain (loss)	1	2	1
Amortization of prior service credit (cost)	5	6	6
Business disposition	0	0	0
Total recognized in OCI, before taxes	4	19	(15)
Total recognized in net periodic benefit cost (credit) and OCI	$ 8	$ 24	$ (9)