Proton Solutions Loans and Investments - MPTC Loan (Details) - USD ($) $ in Millions	1 Months Ended
	Aug. 31, 2018	Jan. 01, 2022	Sep. 27, 2019	Sep. 28, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for- sale securities			$ 58.8	$ 62.5
MPTC loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Cash received from outstanding deferred payment arrangement	$ 6.0
Accounts receivable				$ 0.5
Available-for-sale Securities | MPTC Series B-2 Bonds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Stated rate (as a percent)			8.50%
Available-for- sale securities	22.9
Available-for-sale Securities | MPTC Series B-1 Bonds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Stated rate (as a percent)			7.50%
Available-for- sale securities	$ 25.0
Forecast | Available-for-sale Securities | MPTC Series B-2 Bonds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for- sale securities		$ 33.9
Forecast | Available-for-sale Securities | MPTC Series B-1 Bonds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Available-for- sale securities		$ 32.0