Pension and Other Postretirement Benefits, Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 24, 2016	Jun. 30, 2017	Jun. 24, 2016
Pension Plans [Member]
Components of net periodic benefit cost [Abstract]
Service cost	$ 29	$ 28	$ 58	$ 55
Interest cost	36	34	71	69
Expected return on plan assets	(53)	(51)	(106)	(102)
Amortization of prior service credits	0	0	0	0
Amortization of net loss (gains)	15	13	31	26
Net periodic benefit cost	27	24	54	48
Postretirement Benefit Plans [Member]
Components of net periodic benefit cost [Abstract]
Service cost	0	0	1	1
Interest cost	1	2	2	3
Expected return on plan assets	(1)	(1)	(2)	(2)
Amortization of prior service credits	0	0	0	(1)
Amortization of net loss (gains)	0	0	(1)	0
Net periodic benefit cost	$ 0	$ 1	$ 0	$ 1