Acquisitions and Divestitures Definite-lived intangible assets acquired (Details) - USD ($) $ in Millions	Dec. 30, 2018	Sep. 30, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 1,190.2	$ 1,182.2
Finite-Lived Intangible Assets, Accumulated Amortization	431.0	371.0
Net carrying amount	759.2	811.2
Acquired and reacquired rights
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,089.0	1,081.7
Finite-Lived Intangible Assets, Accumulated Amortization	377.0	320.1
Net carrying amount	$ 712.0	$ 761.6