Fair Value Measurements - Fair Value Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 28, 2019	Sep. 29, 2018
Assets:
Assets measured at fair value on a recurring basis	$ 7.7	$ 10.9
Liabilities:
Liabilities measured at fair value on a recurring basis	9.2	8.0
Quoted Prices in Active Market for Identical Assets (Level 1)
Assets:
Assets measured at fair value on a recurring basis	0.0	0.0
Liabilities:
Liabilities measured at fair value on a recurring basis	0.0	0.0
Significant Other Observable Inputs (Level 2)
Assets:
Assets measured at fair value on a recurring basis	7.7	10.9
Liabilities:
Liabilities measured at fair value on a recurring basis	0.1	0.2
Significant Unobservable Inputs (Level 3)
Assets:
Assets measured at fair value on a recurring basis	0.0	0.0
Liabilities:
Liabilities measured at fair value on a recurring basis	9.1	7.8
Interest rate caps - derivative
Assets:
Interest rate caps - derivative	0.1	7.7
Interest rate caps - derivative | Quoted Prices in Active Market for Identical Assets (Level 1)
Assets:
Interest rate caps - derivative	0.0	0.0
Interest rate caps - derivative | Significant Other Observable Inputs (Level 2)
Assets:
Interest rate caps - derivative	0.1	7.7
Interest rate caps - derivative | Significant Unobservable Inputs (Level 3)
Assets:
Interest rate caps - derivative	0.0	0.0
Interest Rate Swap [Member]
Assets:
Interest rate caps - derivative	4.7
Interest Rate Swap [Member] | Quoted Prices in Active Market for Identical Assets (Level 1)
Assets:
Interest rate caps - derivative	0.0
Interest Rate Swap [Member] | Significant Other Observable Inputs (Level 2)
Assets:
Interest rate caps - derivative	4.7
Interest Rate Swap [Member] | Significant Unobservable Inputs (Level 3)
Assets:
Interest rate caps - derivative	0.0
Stock Options
Assets:
Forward foreign currency contracts	2.0
Stock Options | Assets | Quoted Prices in Active Market for Identical Assets (Level 1)
Assets:
Forward foreign currency contracts	0.0
Stock Options | Assets | Significant Other Observable Inputs (Level 2)
Assets:
Forward foreign currency contracts	2.0
Stock Options | Assets | Significant Unobservable Inputs (Level 3)
Assets:
Forward foreign currency contracts	0.0
Contingent consideration
Liabilities:
Liabilities measured at fair value on a recurring basis	9.1	7.8
Contingent consideration | Quoted Prices in Active Market for Identical Assets (Level 1)
Liabilities:
Liabilities measured at fair value on a recurring basis	0.0	0.0
Contingent consideration | Significant Other Observable Inputs (Level 2)
Liabilities:
Liabilities measured at fair value on a recurring basis	0.0	0.0
Contingent consideration | Significant Unobservable Inputs (Level 3)
Liabilities:
Liabilities measured at fair value on a recurring basis	9.1	7.8
Forward foreign currency contracts
Liabilities:
Liabilities measured at fair value on a recurring basis		0.2
Forward foreign currency contracts | Quoted Prices in Active Market for Identical Assets (Level 1)
Liabilities:
Liabilities measured at fair value on a recurring basis		0.0
Forward foreign currency contracts | Significant Other Observable Inputs (Level 2)
Liabilities:
Liabilities measured at fair value on a recurring basis		0.2
Forward foreign currency contracts | Significant Unobservable Inputs (Level 3)
Liabilities:
Liabilities measured at fair value on a recurring basis		0.0
Forward foreign currency contracts | Assets
Assets:
Interest rate caps - derivative		7.7
Forward foreign currency contracts	0.9	3.2
Forward foreign currency contracts | Assets | Quoted Prices in Active Market for Identical Assets (Level 1)
Assets:
Forward foreign currency contracts	0.0	0.0
Forward foreign currency contracts | Assets | Significant Other Observable Inputs (Level 2)
Assets:
Forward foreign currency contracts	0.9	3.2
Forward foreign currency contracts | Assets | Significant Unobservable Inputs (Level 3)
Assets:
Forward foreign currency contracts	0.0	$ 0.0
Forward foreign currency contracts | Liability
Liabilities:
Liabilities measured at fair value on a recurring basis	0.1
Forward foreign currency contracts | Liability | Quoted Prices in Active Market for Identical Assets (Level 1)
Liabilities:
Liabilities measured at fair value on a recurring basis	0.0
Forward foreign currency contracts | Liability | Significant Other Observable Inputs (Level 2)
Liabilities:
Liabilities measured at fair value on a recurring basis	0.1
Forward foreign currency contracts | Liability | Significant Unobservable Inputs (Level 3)
Liabilities:
Liabilities measured at fair value on a recurring basis	$ 0.0