Composition Of Certain Financial Statement Captions (Schedule Of Prepaid Expenses And Other Current Assets) (Details) - USD ($) $ in Thousands	Dec. 25, 2020	Sep. 25, 2020
Composition Of Certain Financial Statement Captions [Abstract]
Prepaid assets	$ 18,716	$ 17,884
Other current assets	32,674	35,138
Prepaid expenses and other current assets	$ 51,390	$ 53,022

Amount of asset related to consideration paid in advance for costs that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

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Name:	us-gaap_PrepaidExpenseCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant