Financial Derivatives and Hedging - Schedule of Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
AOCI Attributable To Parent, Before Reclassification And Tax [Roll Forward]
Beginning balance	$ 6,162.8	$ 3,627.5	$ 3,824.8	$ 3,628.6
Amount recognized in other comprehensive income on interest rate swaps contracts, net of tax			6.2
Amount reclassified from other comprehensive income into earnings, net of tax			4.6
Ending balance	6,785.4	$ 3,760.4	6,785.4	3,760.4
Accumulated Gain (Loss), Net, Cash Flow Hedge, Before Tax, Parent
AOCI Attributable To Parent, Before Reclassification And Tax [Roll Forward]
Beginning balance			(17.1)
Ending balance	(2.9)		(2.9)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
AOCI Attributable To Parent, Before Reclassification And Tax [Roll Forward]
Beginning balance			(13.0)	$ 0.0
Amount recognized in other comprehensive income on interest rate swap contracts, gross ($6.2 million, net of tax)			8.2
Amount reclassified from other comprehensive income into earnings, gross ($4.6 million, net of tax)			6.0
Ending balance	$ (2.2)		$ (2.2)