Acquisition of Business (Summary of Fair Value of Assets Acquired and Liabilities Assumed - Food Lion) (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Oct. 30, 2016	Dec. 31, 2016	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Business Acquisition [Line Items]
Goodwill		$ 52,330	$ 52,330	$ 52,330
Gain on bargain purchase		$ 23,879	$ 0	$ 23,879	$ 0
Food Lion, LLC [Member]
Business Acquisition [Line Items]
Accounts receivable, net	$ 146
Inventories	7,614
Prepaid expenses and other current assets	1,044
Total current assets	8,804
Property and equipment, net	60,735
Intangibles - favorable leasehold interest	4,583
Total fair value of assets acquired	74,122
Accrued expenses	(428)
Total current liabilities	(428)
Other - unfavorable leasehold interest	(3,738)
Deferred tax liability	(16,663)
Total liabilities	(20,829)
Total fair value of assets acquired and liabilities assumed	53,293
Gain on bargain purchase	$ 23,879