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Pension and Savings Plans - Weighted Average Asset Allocation for Pension Plan Assets (Detail) - USD ($) $ in Thousands | Aug. 26, 2017 | Aug. 27, 2016 | Aug. 29, 2015
--- | --- | --- | ---
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | $ 316,267 | $ 289,386 | $ 238,755
Asset allocation actual | 100.00% | 100.00% |
Asset allocation target | 100.00% | 100.00% |
U.S. Equities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | $ 50,125 | $ 66,008 |
Asset allocation actual | 15.80% | 22.90% |
Asset allocation target | 17.00% | 26.00% |
International Equities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | $ 33,696 | $ 42,023 |
Asset allocation actual | 10.70% | 14.50% |
Asset allocation target | 11.00% | 17.00% |
Emerging Equities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | $ 19,027 | $ 22,848 |
Asset allocation actual | 6.00% | 7.90% |
Asset allocation target | 6.00% | 8.50% |
High Yield Securities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | $ 17,063 | $ 21,445 |
Asset allocation actual | 5.40% | 7.40% |
Asset allocation target | 6.00% | 8.50% |
Fixed Income Securities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | $ 178,650 | $ 99,336 |
Asset allocation actual | 56.50% | 34.30% |
Asset allocation target | 60.00% | 40.00% |
Cash and Cash Equivalents [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | $ 17,706 | $ 37,726 |
Asset allocation actual | 5.60% | 13.00% |
Level 2 [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | $ 316,267 | $ 289,386 |
Level 2 [Member] | U.S. Equities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | 50,125 | 66,008 |
Level 2 [Member] | International Equities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | 33,696 | 42,023 |
Level 2 [Member] | Emerging Equities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | 19,027 | 22,848 |
Level 2 [Member] | High Yield Securities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | 17,063 | 21,445 |
Level 2 [Member] | Fixed Income Securities [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | 178,650 | 99,336 |
Level 2 [Member] | Cash and Cash Equivalents [Member] |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] |  |  |
Asset allocation fair value | $ 17,706 | $ 37,726 |

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- Definition Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items] + References No definition available. + Details
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- Definition Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(i) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2446-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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