Short-Term Investments (Details) - USD ($)	Apr. 03, 2021	Oct. 03, 2020	Apr. 04, 2020
Schedule of Investments [Line Items]
Cash and cash equivalents, Cost Basis	$ 353,049,000	$ 440,258,000
Cash and cash equivalent, Unrealized Gains	0	0
Cash and cash equivalent, Unrealized Losses	0	0
Cash and cash equivalents	353,049,000	440,258,000	$ 369,251,000
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax	100,000
Short-term investments:
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	15,090,000	35,311,000
Available-for-sale securities, Unrealized Gains	38,000	36,000
Available-for-sale securities, Unrealized Losses	0	(1,000)
Available-for-sale securities: Fair Value	15,128,000	35,346,000
Short-term investments: \| U.S. Treasury and agency obligations
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	15,090,000	35,311,000
Available-for-sale securities, Unrealized Gains	38,000	36,000
Available-for-sale securities, Unrealized Losses	0	(1,000)
Available-for-sale securities: Fair Value	$ 15,128,000	$ 35,346,000

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