Note 5 - Goodwill and Other Intangible Assets - Changes in the Carrying Amount of Goodwill (Details)	12 Months Ended
Sep. 26, 2021 USD ($)	Sep. 27, 2020 USD ($)
Goodwill, gross amount	$ 1,617,174,000	$ 1,539,038,000
Accumulated impairment losses	(1,288,729,000)	(1,288,729,000)
Goodwill	328,445,000	250,309,000
Goodwill acquired in business combinations	0	78,136,000
Goodwill, adjustment	1,759,000	0
Goodwill	$ 330,204,000	$ 328,445,000

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.

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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.

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