Restructuring and Cost Reduction Activities - Restructuring and Cost Reduction Reserves Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Restructuring Reserve [Roll Forward]
Liability, beginning balance			$ 160
Restructuring charges	$ 5	$ 96	25	$ 238
Cash payments			(119)
Restructuring Reserve, Accrual Adjustment			10
Liability, ending balance	76		76
Employee related costs
Restructuring Reserve [Roll Forward]
Liability, beginning balance			97
Restructuring charges	1	28	5	135
Cash payments			(43)
Restructuring Reserve, Accrual Adjustment			0
Liability, ending balance	59		59
Pension curtailment (gain) loss, net
Restructuring Reserve [Roll Forward]
Liability, beginning balance			0
Restructuring charges	0	(3)	0	1
Cash payments			0
Restructuring Reserve, Accrual Adjustment			0
Liability, ending balance	0		0
Asset impairment
Restructuring Reserve [Roll Forward]
Liability, beginning balance			0
Restructuring charges	0	0	0	0
Cash payments			0
Restructuring Reserve, Accrual Adjustment			0
Liability, ending balance	0		0
Asset related costs
Restructuring Reserve [Roll Forward]
Liability, beginning balance			0
Restructuring charges	(14)	20	(10)	30
Cash payments			0
Restructuring Reserve, Accrual Adjustment			10
Liability, ending balance	0		0
Other costs
Restructuring Reserve [Roll Forward]
Liability, beginning balance			63
Restructuring charges	18	$ 51	30	$ 72
Cash payments			(76)
Restructuring Reserve, Accrual Adjustment			0
Liability, ending balance	$ 17		$ 17