Date when the acquirer obtains control of the acquiree, in CCYY-MM-DD format.

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In a business combination in which the amount of net identifiable assets acquired and liabilities assumed exceeds the aggregate consideration transferred or to be transferred (as defined), this element represents the amount of gain recognized by the entity.

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The number of businesses acquired by the entity during the period.

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Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

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Number of stores acquired.

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Acquisition of Business (Narrative) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended			0 Months Ended
	Dec. 27, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 27, 2014 entity	Dec. 28, 2013 entity	Dec. 29, 2012	Jun. 11, 2012 store
Business Acquisition [Line Items]
Number of Businesses Acquired									0us-gaap_NumberOfBusinessesAcquired	0us-gaap_NumberOfBusinessesAcquired
Sales Revenue, Goods, Net	$ 713,788us-gaap_SalesRevenueGoodsNet	$ 683,893us-gaap_SalesRevenueGoodsNet	$ 691,875us-gaap_SalesRevenueGoodsNet	$ 687,127us-gaap_SalesRevenueGoodsNet	$ 686,392us-gaap_SalesRevenueGoodsNet	$ 661,412us-gaap_SalesRevenueGoodsNet	$ 662,072us-gaap_SalesRevenueGoodsNet	$ 682,712us-gaap_SalesRevenueGoodsNet	$ 2,776,683us-gaap_SalesRevenueGoodsNet	$ 2,692,588us-gaap_SalesRevenueGoodsNet	$ 2,701,405us-gaap_SalesRevenueGoodsNet
Purchase price									0	0	6,116
Business Combination, Bargain Purchase, Gain Recognized, Amount									0	0	414
Former Genuardi's Stores [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition									Jun. 11, 2012
Sales Revenue, Goods, Net											22,100
Number of stores acquired												3
Purchase price												6,100
Business Combination, Bargain Purchase, Gain Recognized, Amount												$ 414