Pension and Other Postretirement Benefits, Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Pension Plans [Member]
Components of net periodic benefit cost [Abstract]
Service cost	$ 26	$ 25	$ 52	$ 50
Interest cost	36	36	72	71
Expected return on plan assets	(56)	(49)	(112)	(98)
Amortization of net loss (gains)	18	15	37	31
Net periodic benefit cost	24	27	49	54
Postretirement Benefit Plans [Member]
Components of net periodic benefit cost [Abstract]
Service cost	1	0	1	1
Interest cost	1	1	2	2
Expected return on plan assets	(1)	(1)	(2)	(2)
Amortization of net loss (gains)	(1)	0	(2)	(1)
Net periodic benefit cost	$ 0	$ 0	$ (1)	$ 0