Financial Derivatives and Hedging - Schedule of Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Jan. 31, 2021	Jan. 31, 2020
AOCI Attributable To Parent, Before Reclassification And Tax [Roll Forward]
Beginning balance	$ 3,824.8	$ 3,628.6
Amount reclassified from other comprehensive income into earnings, tax expense	0.9
Amount recognized in other comprehensive income on interest rate swaps contracts, tax benefit	0.5
Ending balance	5,989.9	3,730.9
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	(11.2)
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 (net of tax of $0.9 million)	3.8
Amount reclassified from other comprehensive income into earnings, gross (net of tax of $0.5 million)	2.1
Ending balance	$ (8.5)