Commitments and Contingencies - Schedule of Number of Locomotives and Payments under Long-term Maintenance Program (Details) $ in Millions	12 Months Ended
Dec. 30, 2016 USD ($) locomotive	Dec. 25, 2015 USD ($) locomotive	Dec. 26, 2014 USD ($) locomotive
Commitments and Contingencies Disclosure [Abstract]
Amounts Paid \| $	$ 230	$ 233	$ 247
Number of Locomotives \| locomotive	2,243	2,310	1,886

Maintenance costs incurred and directly related to services rendered by an entity during the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(d))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Name:	us-gaap_CostOfServicesMaintenanceCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration