Income Taxes - Reconciliation of Change in Unrecognized Income Tax Benefit (Details) - USD ($) $ in Millions	12 Months Ended
Aug. 31, 2019	Aug. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits balance at beginning of year	$ 4.4	$ 6.0
Additions based on tax positions related to the current year	2.0	0.6
Additions for tax positions of prior years	10.9	1.0
Reductions due to settlements	0.0	(2.2)
Reductions due to lapse of statute of limitations	(0.7)	(1.0)
Unrecognized tax benefits balance at end of year	$ 16.6	$ 4.4

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 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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