Derivative Instruments (Gains Or Losses Recognized On Interest Rate Swap Derivative Instruments) (Details) - USD ($) $ in Thousands	4 Months Ended
Jan. 21, 2018	Jan. 22, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain recognized in OCI	$ 10,291	$ 23,086
Loss reclassified from accumulated OCI into net earnings	1,674	2,066
Interest Rate Swaps \| Derivatives Designated As Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain recognized in OCI	10,291	23,086
Interest Rate Swaps \| Interest Expense, Net \| Derivatives Designated As Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Loss reclassified from accumulated OCI into net earnings	$ 1,674	$ 2,066

Amount before tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph c
-URI http://asc.fasb.org/extlink&oid=84234895&loc=d3e41638-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e689-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580

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