VPT Loans - CPTC Loans (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 02, 2015	Nov. 25, 2015	Sep. 26, 2014	Jun. 30, 2014	Sep. 27, 2013	Sep. 30, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value	$ 93.0		$ 75.6
Available-for-sale Securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitment	0.0		4.7
Fair Value	83.9		75.6
CPTC loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable from CPTC, includes unbilled accounts receivable	25.2		20.1
CPTC loans | Available-for-sale Securities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitment	$ 0.0		4.7
CPTC loan facility, minimum interest rate during initial term (as a percent)	9.00%
CPTC loan facility, amortization period over which monthly payments are calculated after January 1, 2015	15 years
Fair Value	$ 83.9		75.6
CPTC loans | Available-for-sale Securities | Subsequent Event
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maximum Loan Commitment		$ 9.7
CPTC loans | Available-for-sale Securities | LIBOR
Accounts, Notes, Loans and Financing Receivable [Line Items]
CPTC loan facility, interest rate margin (as a percent)	7.00%
CPTC loans | Available-for-sale Securities | Tranche A loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan Facility Maximum Borrowing Capacity						$ 165.3
CPTC loans | Available-for-sale Securities | Varian Medical Systems, Inc. | Subsequent Event
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commitment		$ 4.4
CPTC loans | Available-for-sale Securities | Varian Medical Systems, Inc. | Tranche A loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Significant Sales				$ 38.1
Maximum Loan Commitment				70.3		$ 115.3
CPTC loans | Available-for-sale Securities | Varian Medical Systems, Inc. | Tranche B loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Maximum Loan Commitment				10.0
CPTC loans | Available-for-sale Securities | J.P. Morgan | Tranche A loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Sale Of Portion Of Tranche A Loan Commitment				$ 45.0
CPTC loans | Other Assets | Tranche A loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value	$ 73.5
CPTC loans | Other Assets | Tranche B loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value	$ 10.4				$ 9.4
CPTC loans | Short-term Investments | Tranche A loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Fair Value			$ 66.2