Casualty, Environmental and Other Reserves - Schedule of Casualty, Environmental and Other Reserves (Details) - USD ($) $ in Millions	Jun. 26, 2015	Dec. 26, 2014
Loss Contingencies [Line Items]
Current	$ 146	$ 142
Long-term	280	276
Total	426	418
Total Casualty
Loss Contingencies [Line Items]
Current	66	76
Long-term	211	189
Total	277	265
Personal Injury
Loss Contingencies [Line Items]
Current	58	68
Long-term	147	123
Total	205	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	50	51
Total	55	56
Environmental
Loss Contingencies [Line Items]
Current	58	48
Long-term	37	46
Total	95	94
Other
Loss Contingencies [Line Items]
Current	22	18
Long-term	32	41
Total	$ 54	$ 59