Defined Benefit Plans (Components of Net Periodic Benefit Cost of Other Postretirement Benefit Pension Pans) (Details) - USD ($) $ in Millions	3 Months Ended
	Apr. 02, 2021	Apr. 03, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ (11)	$ (6)
Net periodic cost	0	(1)
Other postretirement benefit plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	(1)	(1)
Amortization of prior service credit	1	0
Net periodic cost	$ 0	$ (1)