Note 4 - Goodwill and Other Intangible Assets - Changes in the Carrying Amount of Goodwill (Details) - USD ($)		6 Months Ended
Mar. 29, 2020	Mar. 29, 2020	Sep. 29, 2019
Goodwill, gross amount			$ 1,539,038,000
Accumulated impairment losses			(1,288,729,000)
Goodwill, beginning of period	$ 313,868,000	$ 313,868,000	$ 250,309,000
Goodwill acquired in business combinations	63,559,000	63,559,000
Goodwill, end of period	$ 313,868,000	$ 313,868,000

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

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-Name Accounting Standards Codification
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-SubTopic 20
-Section 45
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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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Amount before accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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