Employee Benefit Plans - Schedule of Net Benefit Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 30, 2016
Components of expense/ (income) related to net benefit expense [Abstract]
Total Income Included in Other Income - Net	$ (38)	$ (32)	$ 24
Restructuring Charge - Non Operating	56
Pension Benefits
Components of expense/ (income) related to net benefit expense [Abstract]
Service Cost Included in Labor and Fringe	32	36	48
Interest Cost	92	92	119
Expected Return on Plan Assets	(176)	(171)	(157)
Amortization of Net Loss	41	41	48
Amortization of Prior Service Cost	0	0	0
Total Income Included in Other Income - Net	(43)	(38)	10
Net Periodic Benefit Cost	(11)	(2)	58
Restructuring Charge - Non Operating	0	60	0
Settlement (Gain) Loss	(1)	11	(1)
Total (Credit) Expense	(12)	69	57
Post-retirement Benefits
Components of expense/ (income) related to net benefit expense [Abstract]
Service Cost Included in Labor and Fringe	2	2	2
Interest Cost	7	7	12
Expected Return on Plan Assets	0	0	0
Amortization of Net Loss	0	0	3
Amortization of Prior Service Cost	(2)	0	0
Total Income Included in Other Income - Net	5	7	15
Net Periodic Benefit Cost	7	9	17
Restructuring Charge - Non Operating	0	13	0
Settlement (Gain) Loss	0	0	0
Total (Credit) Expense	$ 7	$ 22	$ 17