Fair Value Measurements (Financial Assets And Liabilities Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Thousands		Jan. 19, 2020	Sep. 29, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value		$ 29,857	$ 30,104
Senior Secured Notes Class A2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value of notes		1,300,000
Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	[1]	29,857	30,104
Significant Other Observable Inputs (2) (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	[1]	0	0
Significant Other Observable Inputs (2) (Level 2) | Senior Secured Notes Class A2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value		1,332,000
Significant Unobservable Inputs (2) (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value		0	0
Non Qualified Deferred Compensation Plan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	[2]	29,857	30,104
Non Qualified Deferred Compensation Plan | Quoted Prices In Active Markets For Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value	[1],[2]	29,857	30,104
Non Qualified Deferred Compensation Plan | Significant Other Observable Inputs (2) (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value		0	0
Non Qualified Deferred Compensation Plan | Significant Unobservable Inputs (2) (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value		$ 0	$ 0

[1] We did not have any transfers in or out of Level 1, 2 or 3.

[2] We maintain an unfunded defined contribution plan for key executives and other members of management. The fair value of this obligation is based on the closing market prices of the participants’ elected investments. The obligation is included in “Accrued liabilities” and “Other long-term liabilities” on our condensed consolidated balance sheets.