Composition Of Certain Financial Statement Captions (Schedule Of Accrued Liabilities) (Details) - USD ($) $ in Thousands	Dec. 25, 2020	Sep. 25, 2020
Composition Of Certain Financial Statement Captions [Abstract]
Accrued royalties	$ 1,124	$ 901
Amounts payable to patent administration program partners	97,985	60,427
Accrued compensation and benefits	86,219	89,684
Accrued professional fees	12,182	10,344
Unpaid PP&E additions	14,893	15,102
Accrued customer refunds	5,458	10,053
Other accrued liabilities	32,392	33,463
Total	$ 250,253	$ 219,974

Accrual for Unpaid, Property, Plant and Equipment Additions

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Amounts Payable To Joint Licensing Program Partners

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Composition Of Certain Financial Statement Captions [Abstract]

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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).

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Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for royalties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Amount of liability for consideration received or receivable from customer which is not included in transaction price, when consideration is expected to be refunded to customer.

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Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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