Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

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Nominal or face amount used to calculate payment on derivative.

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Amount, after tax, of reclassification from accumulated other comprehensive income (AOCI) of gain (loss) from increase (decrease) in fair value of net investment hedge.

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Financial Derivatives (Narrative) (Details) £ in Millions, $ in Millions	12 Months Ended
	Aug. 31, 2020 USD ($)	Aug. 31, 2019 USD ($)	Aug. 31, 2018 USD ($)	May 31, 2020 GBP (£)
Derivatives, Fair Value [Line Items]
Outstanding foreign currency forward contracts \| £				£ 15
Foreign Exchange Forward [Member] \| Derivatives Not Designated As Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Outstanding foreign currency forward contracts	$ 0.0	$ 1.8
Fair Value Hedging [Member]
Derivatives, Fair Value [Line Items]
Realized and unrealized gains, net of related income tax effects	7.3	7.0	$ 5.0
Net Investment Hedging [Member]
Derivatives, Fair Value [Line Items]
Foreign currency translation forward contracts, after tax net	1.2	(0.6)	(0.5)
Derivative contracts ineffective amount	0.0	$ 0.0	$ 0.0
Outstanding foreign currency forward contracts	$ 0.0