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Employee Benefit Plans (Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended
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Sep. 25, 2021 | Sep. 26, 2020 | Sep. 28, 2019
Postemployment and Postretirement Benefit Plans [Line Items] |  |  |
Accrued liability for cash bonuses | $ 22,000 | $ 22,300 |
Investment Profit Sharing Plan [Member] |  |  |
Postemployment and Postretirement Benefit Plans [Line Items] |  |  |
Operating and administrative expenses | 5,100 | 4,200 | $ 2,900
Nonqualified Investment Plan [Member] |  |  |
Postemployment and Postretirement Benefit Plans [Line Items] |  |  |
Operating and administrative expenses | 375 | 294 | 224
Cash Bonuses [Member] |  |  |
Postemployment and Postretirement Benefit Plans [Line Items] |  |  |
Operating and administrative expenses | $ 27,200 | 35,900 | $ 11,900
Cash Bonuses [Member] | COVID-19 Pandemic [Member] |  |  |
Postemployment and Postretirement Benefit Plans [Line Items] |  |  |
Operating and administrative expenses |  | $ 15,000 |

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- Definition Carrying value as of the balance sheet date of obligations, excluding pension and other postretirement benefits, incurred through that date and payable for perquisites provided to employees pertaining to services received from them. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e6935-107765 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e6911-107765 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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