Casualty, Environmental and Other Reserves - Schedule of Casualty, Environmental and Other Reserves (Details) (USD $) In Millions, unless otherwise specified	Mar. 27, 2015	Dec. 26, 2014
Loss Contingencies [Line Items]
Current	$ 141	$ 142
Long-term	286	276
Total	427	418
Total Casualty
Loss Contingencies [Line Items]
Current	76	76
Long-term	197	189
Total	273	265
Personal Injury
Loss Contingencies [Line Items]
Current	68	68
Long-term	132	123
Total	200	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	51	51
Total	56	56
Environmental
Loss Contingencies [Line Items]
Current	48	48
Long-term	46	46
Total	94	94
Other
Loss Contingencies [Line Items]
Current	17	18
Long-term	43	41
Total	$ 60	$ 59