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Derivative Instruments (Narrative) (Details) | 4 Months Ended |  |
--- | --- | --- | ---
Jan. 21, 2018 USD ($) | Jan. 22, 2017 USD ($) | Jun. 15, 2015 USD ($) agreements | Apr. 14, 2014 USD ($) agreements
Derivative [Line Items] |  |  |  |
Interest rate derivatives held | agreements |  |  | 11 | 9
Interest Rate Swaps |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount |  |  | $ 200,000,000 | $ 300,000,000
Interest rate swaps hedge ineffectiveness | $ 0 | $ 0 |  |
Interest Rate Swap 1 |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative, Notional Amount |  |  | $ 500,000,000 |

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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- Definition The net gain (loss) during the reporting period due to ineffectiveness in interest rate cash flow hedges. Recognized in earnings. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
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- Definition Number of interest rate derivative instruments held by the entity at the reporting date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5579245-113959 + Details
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- Details
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