Casualty, Environmental and Other Reserves - Schedule of Casualty, Environmental and Other Reserves (Details) - USD ($) $ in Millions	Sep. 25, 2015	Dec. 26, 2014
Loss Contingencies [Line Items]
Current	$ 146	$ 142
Long-term	270	276
Total	416	418
Total Casualty
Loss Contingencies [Line Items]
Current	66	76
Long-term	207	189
Total	273	265
Personal Injury
Loss Contingencies [Line Items]
Current	58	68
Long-term	145	123
Total	203	191
Occupational
Loss Contingencies [Line Items]
Current	3	3
Long-term	14	15
Total	17	18
Asbestos
Loss Contingencies [Line Items]
Current	5	5
Long-term	48	51
Total	53	56
Environmental
Loss Contingencies [Line Items]
Current	58	48
Long-term	30	46
Total	88	94
Other
Loss Contingencies [Line Items]
Current	22	18
Long-term	33	41
Total	$ 55	$ 59