Income Taxes - Reconciliation of Total Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 35.8	$ 53.4	$ 57.2
Additions for tax positions related to the current year	0.0	0.2	0.0
Additions for tax positions related to prior years	3.6	0.0	16.4
Reductions for tax positions related to prior years	0.0	(9.0)	(0.1)
Reductions for lapse of statute of limitations	(3.9)	(8.7)	(19.7)
Settlements	(0.3)	(0.1)	(0.3)
Ending Balance	$ 35.3	$ 35.8	$ 53.4

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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