For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

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- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

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- Details

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- Details

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- Details

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Revenue Recognition (Schedule Of Sales By Type Of Product) (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 28, 2019 USD ($)	Sep. 28, 2019 USD ($)	Jun. 29, 2019 USD ($)	Mar. 30, 2019 USD ($)	Dec. 29, 2018 USD ($)	Sep. 29, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 28, 2019 USD ($) segment	Dec. 29, 2018 USD ($)	Dec. 30, 2017 USD ($)
Disaggregation of Revenue [Line Items]
Number of reportable segments \| segment									1
Total net sales	$ 902,392	$ 876,222	$ 887,967	$ 876,718	$ 892,988	$ 869,076	$ 871,100	$ 876,106	$ 3,543,299	$ 3,509,270	$ 3,466,807
Revenue Benchmark [Member] \| Product Concentration Risk [Member]
Disaggregation of Revenue [Line Items]
Concentration percent									100.00%	100.00%	100.00%
Grocery [Member] \| Revenue Benchmark [Member] \| Product Concentration Risk [Member]
Disaggregation of Revenue [Line Items]
Total net sales									$ 3,068,754	$ 3,063,218	$ 3,041,481
Concentration percent									86.60%	87.30%	87.70%
Pharmacy [Member] \| Revenue Benchmark [Member] \| Product Concentration Risk [Member]
Disaggregation of Revenue [Line Items]
Total net sales									$ 337,233	$ 314,584	$ 309,079
Concentration percent									9.50%	9.00%	8.90%
Fuel [Member] \| Revenue Benchmark [Member] \| Product Concentration Risk [Member]
Disaggregation of Revenue [Line Items]
Total net sales									$ 127,828	$ 125,993	$ 109,467
Concentration percent									3.60%	3.60%	3.20%
Manufacturing [Member] \| Revenue Benchmark [Member] \| Product Concentration Risk [Member]
Disaggregation of Revenue [Line Items]
Total net sales									$ 9,484	$ 5,475	$ 6,780
Concentration percent									0.30%	0.10%	0.20%