Proton Solutions Loans and Investments - Schedule of VPT Loans (Details) - USD ($) $ in Millions	Oct. 02, 2020	Sep. 27, 2019	Dec. 06, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitment	$ 0.0	$ 0.0
Available-for- sale securities	44.9	58.8
Term loan	0.0	44.0
MPTC Series B-1 Bonds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitment, bonds	0.0	0.0
Available-for- sale securities	18.9	27.1
MPTC Series B-2 Bonds
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitment, bonds	0.0	0.0
Available-for- sale securities	20.6	25.1
APTC securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitment	0.0	0.0
Available-for- sale securities	5.4	6.6
Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes, Loans and Financing Receivable, Net	61.9	57.1
Commitment	0.0	0.0
Loans Receivable | NYPC loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Long term	34.9	31.8
Commitment	0.0	0.0
Loans Receivable | RPTC senior secured debt
Accounts, Notes, Loans and Financing Receivable [Line Items]
Senior secured debt	25.2	23.5
Commitment	0.0	0.0
Loans Receivable | Proton International LLC loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Long term	1.8	1.8
Commitment	0.0	0.0
Loans Receivable | C P T C
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loan			$ 112.0
Term Loan | C P T C
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitment	0.0	1.9
Term loan	11.8	$ 49.3
Term Loan | C P T C | Prepaid Expenses and Other Current Assets
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loan	5.3
Term Loan | C P T C | Other Assets [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Term loan	$ 44.0