Marketable Securities Schedule of Available-for-sale Securities (Details) - USD ($) $ in Millions	3 Months Ended
	Jan. 01, 2021	Oct. 02, 2020
Debt Securities, Available-for-sale [Line Items]
Document Period End Date	Jan. 01, 2021
US Treasury and Government [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	$ 0.2	$ 0.3
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	$ 0.1	$ 0.2