Employee Benefit Plans - Schedule of Net Benefit Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 30, 2016	Dec. 25, 2015
Components of expense/ (income) related to net benefit expense [Abstract]
Special Termination Benefits - Workforce Reduction Program/Curtailment	$ 56
Pension Plans
Components of expense/ (income) related to net benefit expense [Abstract]
Service Cost	36	$ 48	$ 45
Interest Cost	92	119	116
Expected Return on Plan Assets	(171)	(157)	(162)
Amortization of Net Loss	41	48	70
Amortization of Prior Service Cost	0	0	0
Net Periodic Benefit Expense	(2)	58	69
Special Termination Benefits - Workforce Reduction Program/Curtailment	60	0	7
Settlement Loss (Gain)	11	(1)	(2)
Total Expense	69	57	74
Post-retirement Benefits
Components of expense/ (income) related to net benefit expense [Abstract]
Service Cost	2	2	2
Interest Cost	7	12	12
Expected Return on Plan Assets	0	0	0
Amortization of Net Loss	0	3	4
Amortization of Prior Service Cost	0	0	(1)
Net Periodic Benefit Expense	9	17	17
Special Termination Benefits - Workforce Reduction Program/Curtailment	13	0	0
Settlement Loss (Gain)	0	0	0
Total Expense	$ 22	$ 17	$ 17