Employee Benefit Plans - Components of Expense/(Income) Related to Net Benefit Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 25, 2016
Pension Benefits
Components of expense/ (income) related to net benefit expense:
Service Cost	$ 11	$ 12
Interest Cost	23	30
Expected Return on Plan Assets	(42)	(39)
Amortization of Net Loss	11	12
Net Periodic Benefit Cost	3	15
Special Termination Benefits – Workforce Reduction Program	50	0
Total Expense	53	15
Other Post-retirement Benefits
Components of expense/ (income) related to net benefit expense:
Interest Cost	2	3
Amortization of Net Loss	0	1
Net Periodic Benefit Cost	2	4
Special Termination Benefits – Workforce Reduction Program	13	0
Total Expense	$ 15	$ 4