Fair Value Measurements - Fair Value Assets and Liabilities Measured on Recurring Basis (Detail) (USD $) In Millions, unless otherwise specified	Sep. 27, 2014	Sep. 28, 2013
Assets:
Assets measured at fair value on a recurring basis	$ 39.8	$ 25.0
Liabilities:
Liabilities measured at fair value on a recurring basis	35.8	42.4
Equity Security [Member]
Assets:
Assets measured at fair value on a recurring basis	24.4	18.1
Mutual Funds [Member]
Assets:
Assets measured at fair value on a recurring basis	15.4	6.9
Deferred Compensation Liabilities [Member]
Liabilities:
Liabilities measured at fair value on a recurring basis	35.8	38.6
Contingent Consideration [Member]
Liabilities:
Liabilities measured at fair value on a recurring basis		3.8
Quoted Prices in Active Market for Identical Assets (Level 1) [Member]
Assets:
Assets measured at fair value on a recurring basis	39.8	25.0
Liabilities:
Liabilities measured at fair value on a recurring basis	35.8	38.6
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | Equity Security [Member]
Assets:
Assets measured at fair value on a recurring basis	24.4	18.1
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | Mutual Funds [Member]
Assets:
Assets measured at fair value on a recurring basis	15.4	6.9
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | Deferred Compensation Liabilities [Member]
Liabilities:
Liabilities measured at fair value on a recurring basis	35.8	38.6
Quoted Prices in Active Market for Identical Assets (Level 1) [Member] | Contingent Consideration [Member]
Liabilities:
Liabilities measured at fair value on a recurring basis		0
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Assets measured at fair value on a recurring basis	0	0
Liabilities:
Liabilities measured at fair value on a recurring basis	0	0
Significant Other Observable Inputs (Level 2) [Member] | Equity Security [Member]
Assets:
Assets measured at fair value on a recurring basis	0	0
Significant Other Observable Inputs (Level 2) [Member] | Mutual Funds [Member]
Assets:
Assets measured at fair value on a recurring basis	0	0
Significant Other Observable Inputs (Level 2) [Member] | Deferred Compensation Liabilities [Member]
Liabilities:
Liabilities measured at fair value on a recurring basis	0	0
Significant Other Observable Inputs (Level 2) [Member] | Contingent Consideration [Member]
Liabilities:
Liabilities measured at fair value on a recurring basis		0
Fair Value, Inputs, Level 3 [Member]
Assets:
Assets measured at fair value on a recurring basis	0	0
Liabilities:
Liabilities measured at fair value on a recurring basis	0	3.8
Fair Value, Inputs, Level 3 [Member] | Equity Security [Member]
Assets:
Assets measured at fair value on a recurring basis	0	0
Fair Value, Inputs, Level 3 [Member] | Mutual Funds [Member]
Assets:
Assets measured at fair value on a recurring basis	0	0
Fair Value, Inputs, Level 3 [Member] | Deferred Compensation Liabilities [Member]
Liabilities:
Liabilities measured at fair value on a recurring basis	0	0
Fair Value, Inputs, Level 3 [Member] | Contingent Consideration [Member]
Liabilities:
Liabilities measured at fair value on a recurring basis		$ 3.8