Pensions and Other Benefit Plans - Narrative (Details) - USD ($) $ in Millions			12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 03, 2021	Dec. 29, 2019	Dec. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Percentage of corridor of greater of market value of assets			10.00%
Accumulated benefit obligation unfunded plans			$ 8,800	$ 4,300
Projected benefit obligation, unfunded plans			9,800	5,200
Plan Assets			4,400	900
Fair value of company's common stock directly held in plan assets			$ 946	$ 984
Percentage of company's common stock to plan asset			2.50%	3.10%
Defined benefit plan, plan assets, accounting policy election, measurement date	Dec. 31, 2020	Dec. 31, 2019
Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Plan Assets			$ 38,195	$ 32,201	$ 26,818
Other Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Plan Assets			90	115	$ 180
U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Contribution to pension plans			441
International Plans
Defined Benefit Plan Disclosure [Line Items]
Contribution to pension plans			429
Commingled funds | Level 2 | Other Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Plan Assets			$ 90	84
Short-term Investments | Level 2 | Other Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Plan Assets				$ 31
Maximum | Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Retirement plan benefits Employee compensation Period			5 years