Investments & Fair Value Measurements - Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 29, 2024	Sep. 29, 2023
Debt Securities, Available-for-Sale [Line Items]
Less Than 12 Months, Fair Value	$ 116,872	$ 136,660
Less Than 12 Months, Gross Unrealized Losses	(457)	(921)
12 Months or Greater, Fair Value	39,578	63,035
12 Months or Greater, Gross Unrealized Loss	(793)	(1,947)
U.S. agency securities
Debt Securities, Available-for-Sale [Line Items]
Less Than 12 Months, Fair Value	0	853
Less Than 12 Months, Gross Unrealized Losses	0	(7)
12 Months or Greater, Fair Value	0	0
12 Months or Greater, Gross Unrealized Loss	0	0
Government bonds
Debt Securities, Available-for-Sale [Line Items]
Less Than 12 Months, Fair Value	29,859	26,756
Less Than 12 Months, Gross Unrealized Losses	(183)	(247)
12 Months or Greater, Fair Value	19,336	40,235
12 Months or Greater, Gross Unrealized Loss	(440)	(1,183)
Commercial paper
Debt Securities, Available-for-Sale [Line Items]
Less Than 12 Months, Fair Value	11,267	5,840
Less Than 12 Months, Gross Unrealized Losses	(20)	(3)
12 Months or Greater, Fair Value	0	0
12 Months or Greater, Gross Unrealized Loss	0	0
Corporate bonds
Debt Securities, Available-for-Sale [Line Items]
Less Than 12 Months, Fair Value	64,105	79,846
Less Than 12 Months, Gross Unrealized Losses	(200)	(461)
12 Months or Greater, Fair Value	14,763	14,634
12 Months or Greater, Gross Unrealized Loss	(275)	(558)
Municipal debt securities
Debt Securities, Available-for-Sale [Line Items]
Less Than 12 Months, Fair Value	11,641	23,365
Less Than 12 Months, Gross Unrealized Losses	(54)	(203)
12 Months or Greater, Fair Value	5,479	8,166
12 Months or Greater, Gross Unrealized Loss	$ (78)	$ (206)