Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 26, 2015	Jun. 27, 2014	Jun. 26, 2015	Jun. 27, 2014
Pension Benefits
Components of expense/ (income) related to net benefit expense:
Service Cost	$ 11	$ 11	$ 22	$ 22
Interest Cost	29	31	58	62
Expected Return on Plan Assets	(41)	(42)	(81)	(83)
Amortization of Net Loss	18	14	35	28
Net Periodic Benefit Cost	17	14	34	29
Special Termination Employee Benefits	0	0	7	0
Total Expense	17	14	41	29
Other Post-retirement Benefits
Components of expense/ (income) related to net benefit expense:
Service Cost	0	0	1	1
Interest Cost	3	4	7	7
Amortization of Net Loss	1	2	2	3
Amortization of Prior Service Costs	0	(1)	0	(1)
Total Expense	$ 4	$ 5	$ 10	$ 10