Commitments And Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
Oct. 03, 2025	Sep. 27, 2024	Sep. 29, 2023
Supply Commitment [Line Items]
Asset impairment charges	$ 0.0	$ 147.9	$ 64.5
Recorded Unconditional Purchase Obligation [Line Items]
Prepaid expenses, current	201.0	234.8
Supply capacity deposits
Supply Commitment [Line Items]
Asset impairment charges			$ 47.5
Wafer purchases
Recorded Unconditional Purchase Obligation [Line Items]
Deposits assets	26.4	167.8
Prepaid expenses	26.4	167.8
Deposits assets, current	7.7	144.7
Prepaid expenses, current	7.7	144.7
Deposits assets, noncurrent	18.7	23.1
Prepaid expenses, noncurrent	$ 18.7	$ 23.1

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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