Pension, Retiree Medical and Savings Plans (Selected Financial Information for Pension and Retiree Medical Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Pension Plans, Defined Benefit
Change in fair value of plan assets
Employer contributions/funding	$ 672	$ 1,615	$ 164
Retiree Medical Plan
Change in projected benefit liability
Liability at beginning of year	996	1,187
Service cost	23	32	28
Interest cost	36	34	36
Experience loss/(gain)	36	(147)
Special termination benefits		1
Other, including foreign currency adjustment	2	(3)
Liability at end of year	988	996	1,187
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(105)	(108)
Change in fair value of plan assets
Fair value at beginning of year	285	321
Actual return on plan assets	78	(21)
Employer contributions/funding	44	93	56
Defined Benefit Plan, Plan Assets, Benefits Paid	(105)	(108)
Fair value at end of year	302	285	321
Funded status	(686)	(711)
Amounts recognized
Other current liabilities	(58)	(41)
Other liabilities	(628)	(670)
Net amount recognized	(686)	(711)
Amounts included in accumulated other comprehensive loss (pre-tax)
Net loss/(gain)	(285)	(287)
Prior service cost/(credit)	(32)	(51)
Total	(317)	(338)
Changes recognized in net (gain)/loss included in other comprehensive loss
Net (gain)/loss arising in current year	(24)	(107)
Amortization and settlement recognition	27	8
Foreign currency translation loss/(gain)	(1)	1
Total	2	(98)
Domestic Plan [Member]
Change in projected benefit liability
Liability at beginning of year	13,807	14,777
Service cost	381	431	401
Interest cost	543	482	468
Plan amendments	15	83
Experience loss/(gain)	2,091	(972)
Settlement/curtailment	(1,268)	(74)
Special termination benefits	2	36
Liability at end of year	15,230	13,807	14,777
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(341)	(956)
Change in fair value of plan assets
Fair value at beginning of year	12,258	12,582
Actual return on plan assets	3,101	(789)
Employer contributions/funding	550	1,495
Defined Benefit Plan, Plan Assets, Benefits Paid	(341)	(956)
Defined Benefit Plan, Plan Assets, Payment for Settlement	(1,266)	(74)
Fair value at end of year	14,302	12,258	12,582
Funded status	(928)	(1,549)
Amounts recognized
Other assets	744	185
Other current liabilities	(52)	(107)
Other liabilities	(1,620)	(1,627)
Net amount recognized	(928)	(1,549)
Amounts included in accumulated other comprehensive loss (pre-tax)
Net loss/(gain)	3,516	4,093
Prior service cost/(credit)	114	109
Total	3,630	4,202
Changes recognized in net (gain)/loss included in other comprehensive loss
Net (gain)/loss arising in current year	(120)	760
Amortization and settlement recognition	(457)	(187)
Total	(577)	573
Accumulated benefit obligation at end of year	14,255	12,890
Foreign Plan [Member]
Change in projected benefit liability
Liability at beginning of year	3,098	3,490
Service cost	73	92	91
Interest cost	97	93	89
Plan amendments	1	2
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	2	2
Experience loss/(gain)	515	(230)
Settlement/curtailment	(31)	(35)
Special termination benefits		2
Other, including foreign currency adjustment	98	(204)
Liability at end of year	3,753	3,098	3,490
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(100)	(114)
Change in fair value of plan assets
Fair value at beginning of year	3,090	3,460
Actual return on plan assets	551	(136)
Employer contributions/funding	122	120
Participant contributions	2	2
Defined Benefit Plan, Plan Assets, Benefits Paid	(100)	(114)
Defined Benefit Plan, Plan Assets, Payment for Settlement	(31)	(32)
Other, including foreign currency adjustment	98	(210)
Fair value at end of year	3,732	3,090	$ 3,460
Funded status	(21)	(8)
Amounts recognized
Other assets	99	81
Other current liabilities	(1)	(1)
Other liabilities	(119)	(88)
Net amount recognized	(21)	(8)
Amounts included in accumulated other comprehensive loss (pre-tax)
Net loss/(gain)	914	780
Prior service cost/(credit)		(1)
Total	914	779
Changes recognized in net (gain)/loss included in other comprehensive loss
Net (gain)/loss arising in current year	152	103
Amortization and settlement recognition	(44)	(56)
Foreign currency translation loss/(gain)	26	(49)
Total	134	(2)
Accumulated benefit obligation at end of year	$ 3,441	$ 2,806