Other Comprehensive Income / (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 25, 2016	Mar. 27, 2015
Equity [Abstract]
Total comprehensive earnings, net of tax	$ 363	$ 440
Pension and Other Post-Employment Benefits
Other Comprehensive Income (Loss)
Beginning balance	(601)
Loss Before Reclassifications	0
Amounts Reclassified to Net Earnings	13
Tax Expense	(5)
Total Other Comprehensive Income (Loss)	8
Ending balance	(593)
Other
Other Comprehensive Income (Loss)
Beginning balance	(64)
Loss Before Reclassifications	(1)
Amounts Reclassified to Net Earnings	0
Tax Expense	0
Total Other Comprehensive Income (Loss)	(1)
Ending balance	(65)
Accumulated Other Comprehensive Income (Loss)
Other Comprehensive Income (Loss)
Beginning balance	(665)
Loss Before Reclassifications	(1)
Amounts Reclassified to Net Earnings	13
Tax Expense	(5)
Total Other Comprehensive Income (Loss)	7
Ending balance	$ (658)