Casualty, Environmental and Other Reserves - Schedule of Casualty, Environmental and Other Reserves (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 30, 2016
Loss Contingencies [Line Items]
Current	$ 114	$ 115
Long-term	252	259
Total	366	374
Total Casualty
Loss Contingencies [Line Items]
Current	53	53
Long-term	173	176
Total	226	229
Personal Injury
Loss Contingencies [Line Items]
Current	46	46
Long-term	122	124
Total	168	170
Occupational(a)
Loss Contingencies [Line Items]
Current	7	7
Long-term	51	52
Total	58	59
Environmental
Loss Contingencies [Line Items]
Current	42	42
Long-term	51	53
Total	93	95
Other
Loss Contingencies [Line Items]
Current	19	20
Long-term	28	30
Total	$ 47	$ 50