Nature of Operations and Significant Accounting Policies - Narrative (Details) mi in Thousands, $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 24, 2016 USD ($) state mi	Jun. 26, 2015	Jun. 24, 2016 USD ($) state mi	Jun. 26, 2015	Dec. 30, 2016	Dec. 25, 2015 USD ($)
Background
Total number of rail route miles | mi	21		21
Number of states rail network serves | state	23		23
Fiscal Year
Number of days in fiscal year						364 days
Number of days in fiscal quarter	91 days	91 days
Number of days in fiscal quarter YTD			91 days	91 days
Allowance for Doubtful Accounts
Allowance for doubtful accounts	$ 30		$ 30			$ 37
Scenario Forecast
Fiscal Year
Number of days in fiscal year					371 days
New Accounting Pronouncement, Early Adoption, Effect
Allowance for Doubtful Accounts
Deferred tax assets net, current	$ (132)		$ (132)			$ (126)