Defined Benefit Plans (Components of Net Periodic Benefit Cost of Other Postretirement Benefit Pension Pans) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2021	Oct. 02, 2020	Oct. 01, 2021	Oct. 02, 2020
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ (11)	$ (11)	$ (33)	$ (28)
Net periodic cost	(2)	(7)	(2)	(14)
Other postretirement benefit plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	(1)	(1)	(2)	(3)
Amortization of actuarial loss	(1)	0	(2)	0
Amortization of prior service credit	1	0	2	1
Net periodic cost	$ (1)	$ (1)	$ (2)	$ (2)