Restructuring and Cost Reduction Activities - Restructuring and Cost Reduction Reserves Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Restructuring Reserve [Roll Forward]
Liability, beginning balance			$ 160
Restructuring charges	$ 34	$ 1	59	$ 239
Cash payments			(158)
Non-cash charges and other			22
Liability, ending balance	83		83
Employee related costs
Restructuring Reserve [Roll Forward]
Liability, beginning balance			97
Restructuring charges	17	31	22	166
Cash payments			(52)
Non-cash charges and other			0
Liability, ending balance	67		67
Pension curtailment (gain) loss, net
Restructuring Reserve [Roll Forward]
Liability, beginning balance			0
Restructuring charges	(30)	(134)	(30)	(133)
Cash payments			0
Non-cash charges and other			30
Liability, ending balance	0		0
Asset impairment
Restructuring Reserve [Roll Forward]
Liability, beginning balance			0
Restructuring charges	14	0	14	0
Cash payments			0
Non-cash charges and other			(14)
Liability, ending balance	0		0
Asset related costs
Restructuring Reserve [Roll Forward]
Liability, beginning balance			0
Restructuring charges	10	38	0	68
Cash payments			(3)
Non-cash charges and other			6
Liability, ending balance	3		3
Other costs
Restructuring Reserve [Roll Forward]
Liability, beginning balance			63
Restructuring charges	23	$ 66	53	$ 138
Cash payments			(103)
Non-cash charges and other			0
Liability, ending balance	$ 13		$ 13