Financial Instruments and Fair Value Measurements (Schedule of Carrying Amount and Fair Value of Long-term Debt) (Details) (USD $) In Millions, unless otherwise specified	Dec. 26, 2014	Sep. 26, 2014
Carrying Value | Secured Debt | Receivable Securitization
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 150.0	$ 150.0
Carrying Value | Secured Debt | 2.85% Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	2.9	3.1
Carrying Value | Secured Debt | Term Loan and New Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	1,987.3	1,990.3
Carrying Value | Secured Debt | 4.00% Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	10.0	10.8
Carrying Value | Senior Notes | 3.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	300.0	300.0
Carrying Value | Senior Notes | 5.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	900.0	900.0
Carrying Value | Senior Notes | 4.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	598.4	598.3
Carrying Value | Debentures | 9.50% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	10.4	10.4
Carrying Value | Debentures | 8.00% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	4.7	8.0
Fair Value | Secured Debt | Receivable Securitization
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	150.0	150.0
Fair Value | Secured Debt | 2.85% Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	2.9	3.1
Fair Value | Secured Debt | Term Loan and New Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	1,950.6	1,970.4
Fair Value | Secured Debt | 4.00% Term Loan
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	10.0	10.8
Fair Value | Senior Notes | 3.50% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	289.2	290.2
Fair Value | Senior Notes | 5.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	926.9	907.3
Fair Value | Senior Notes | 4.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	560.0	563.8
Fair Value | Debentures | 9.50% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	12.6	14.2
Fair Value | Debentures | 8.00% Debenture
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 5.3	$ 10.2