Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jul. 31, 2021	Oct. 31, 2023	Oct. 31, 2022	Oct. 31, 2021	Jan. 31, 2021
Operating Loss Carryforwards [Line Items]
Deferred tax asset, intra-entity sale of certain intellectual property rights					$ 1,987.9
Remeasurement of deferred tax assets from UK rate change	$ (536.7)	$ 0.0	$ 0.0	$ (536.7)
Unrecognized tax benefits that would impact the effective tax rate		323.2	324.3	336.5
Accrued gross interest and penalties related to uncertain tax positions		5.8	$ 5.4	$ 6.4
Significant change in unrecognized tax benefits that is reasonably possible during the next twelve months		8.1
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		78.7
Federal net operating losses expiring		46.0
Federal net operating losses not subject to expiration		32.7
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		$ 87.1