Short-Term Investments (Details) - USD ($)	Jul. 04, 2020	Sep. 28, 2019	Jun. 29, 2019
Schedule of Investments [Line Items]
Cash and cash equivalents, Cost Basis	$ 378,992,000	$ 305,833,000
Cash and cash equivalent, Unrealized Gains	0	0
Cash and cash equivalent, Unrealized Losses	0	0
Cash and cash equivalents	378,992,000	305,833,000	$ 316,458,000
Short-term investments:
Schedule of Investments [Line Items]
Available-for-sale securities, Unrealized Gains	0	0
Available-for-sale securities, Unrealized Losses	0	0
Available-for-sale Securities, Total	41,898,000	120,000
Short-term investments: \| U.S. Treasury and agency obligations
Schedule of Investments [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	115,000	120,000
Available-for-sale securities, Unrealized Gains	0	0
Available-for-sale securities, Unrealized Losses	0	0
Available-for-sale securities: Fair Value	115,000	$ 120,000
Time Deposits	$ 41,783,000

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