Employee Benefits - Components of Plan Benefit Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Global | Pension
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 9	$ 22
Interest cost	45	42
Expected return on plan assets	(85)	(92)
Amortization of unrecognized prior service cost (gain)	2	2
Recognized net (gain) loss	1	(9)
Total plan benefit (income) expense	(28)	(35)
Global | Postemployment
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1
Interest cost	0	0
Recognized net (gain) loss	(1)	(1)
Total plan benefit (income) expense	0	0
United States and Canada | Other Nonpension Postretirement
Defined Benefit Plan Disclosure [Line Items]
Service cost	3	5
Interest cost	10	9
Expected return on plan assets	(21)	(24)
Amortization of unrecognized prior service cost (gain)	(2)	(2)
Total plan benefit (income) expense	$ (10)	$ (12)