Other Comprehensive Income / (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 25, 2015	Sep. 26, 2014	Sep. 25, 2015	Sep. 26, 2014
Equity [Abstract]
Total comprehensive earnings, net of tax	$ 518	$ 518	$ 1,523	$ 1,476
Pension and Other Post-Employment Benefits
Other Comprehensive Income (Loss)
Balance December 26, 2014, Net of Tax			(611)
Loss Before Reclassifications			0
Amounts Reclassified to Net Earnings			55
Tax Expense			(22)
Total Other Comprehensive Income (Loss)			33
Balance September 25, 2015, Net of Tax	(578)		(578)
Other
Other Comprehensive Income (Loss)
Balance December 26, 2014, Net of Tax			(55)
Loss Before Reclassifications			(11)
Amounts Reclassified to Net Earnings			(1)
Tax Expense			0
Total Other Comprehensive Income (Loss)			(12)
Balance September 25, 2015, Net of Tax	(67)		(67)
Accumulated Other Comprehensive Income (Loss)
Other Comprehensive Income (Loss)
Balance December 26, 2014, Net of Tax			(666)
Loss Before Reclassifications			(11)
Amounts Reclassified to Net Earnings			54
Tax Expense			(22)
Total Other Comprehensive Income (Loss)			21
Balance September 25, 2015, Net of Tax	$ (645)		$ (645)