Financial Instruments and Fair Value Measurements (Schedule of Fair Value of Assets and Liabilities Measured on a Recurring Basis) (Details) (Recurring, USD $) In Millions, unless otherwise specified	Mar. 27, 2015	Sep. 26, 2014
Assets:
Debt and equity securities held in rabbi trusts	$ 36.8	$ 35.7
Foreign exchange forward and option contracts	0.3
Total assets at fair value	37.1	35.7
Liabilities:
Deferred compensation liabilities	19.1	15.0
Contingent consideration and acquired contingent liabilities	198.2	202.8
Foreign exchange forward and option contracts	5.4	0.2
Total liabilities at fair value	222.7	218.0
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Debt and equity securities held in rabbi trusts	25.0	22.9
Foreign exchange forward and option contracts	0.3
Total assets at fair value	25.3	22.9
Liabilities:
Deferred compensation liabilities	0	0
Contingent consideration and acquired contingent liabilities	0	0
Foreign exchange forward and option contracts	5.4	0.2
Total liabilities at fair value	5.4	0.2
Significant Other Observable Inputs (Level 2)
Assets:
Debt and equity securities held in rabbi trusts	11.8	12.8
Foreign exchange forward and option contracts	0
Total assets at fair value	11.8	12.8
Liabilities:
Deferred compensation liabilities	19.1	15.0
Contingent consideration and acquired contingent liabilities	0	0
Foreign exchange forward and option contracts	0	0
Total liabilities at fair value	19.1	15.0
Significant Unobservable Inputs (Level 3)
Assets:
Debt and equity securities held in rabbi trusts	0	0
Foreign exchange forward and option contracts	0
Total assets at fair value	0	0
Liabilities:
Deferred compensation liabilities	0	0
Contingent consideration and acquired contingent liabilities	198.2	202.8
Foreign exchange forward and option contracts	0	0
Total liabilities at fair value	$ 198.2	$ 202.8