Casualty, Environmental and Other Reserves (Occupational and Asbestos Claims) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 26, 2014 claims	Dec. 27, 2013 claims
Occupational Casualty and Asbestos Issues [Member]
Loss Contingency, Claims Quantities [Roll Forward]
Open Claims - Beginning of Year	392	523
New Claims Filed	136	165
Claims Settled	(128)	(146)
Claims Dismissed	(130)	(150)
Open Claims - End of Year	270	392
Occupational [Member]
Loss Contingencies [Line Items]
Time period for estimating probable claims (in years)	7 years
Total liability	18	23
Occupational [Member] | Incurred but not reported claims [Member]
Loss Contingencies [Line Items]
Incurred but not reported claims	12	15
Occupational [Member] | Asserted claims [Member]
Loss Contingencies [Line Items]
Asserted claims	6	8
Asbestos [Member]
Loss Contingencies [Line Items]
Total liability	56	50
Asbestos [Member] | Incurred but not reported claims [Member]
Loss Contingencies [Line Items]
Incurred but not reported claims	45	35
Asbestos [Member] | Asserted claims [Member]
Loss Contingencies [Line Items]
Asserted claims	11	15
Carpal Tunnel Claims [Member]
Loss Contingencies [Line Items]
Time period for estimating probable claims (in years)	3 years
Minimum [Member] | Asbestos [Member]
Loss Contingencies [Line Items]
Loss contingency, latency period (in years)	10 years
Maximum [Member] | Asbestos [Member]
Loss Contingencies [Line Items]
Loss contingency, latency period (in years)	40 years