Derivative Instruments - Effect of Derivative Instruments on Consolidated Statements of Income (Detail) - Cash Flow Hedging - USD ($) $ in Thousands	12 Months Ended
Aug. 31, 2018	Aug. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Gain recognized in income on derivatives	$ 1,051	$ 3,230
Gain (loss) recognized in OCI on derivatives (effective portion)	(119)	3,173
Gain (loss) reclassified accumulated OCI income (effective portion)	418	(4,701)
Gain (loss) recognized on derivative (ineffective portion and amount excluded from effectiveness testing)	1,160	(2,595)
Foreign Exchange Forward
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivatives (effective portion)	(658)	1,746
Foreign Exchange Forward \| Interest and Foreign Exchange
Derivative Instruments, Gain (Loss) [Line Items]
Gain recognized in income on derivatives	1,052	3,207
Foreign Exchange Forward \| Sales
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified accumulated OCI income (effective portion)	1,145	(3,980)
Gain (loss) recognized on derivative (ineffective portion and amount excluded from effectiveness testing)	854	(2,843)
Foreign Exchange Forward \| Cost Of Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivatives (effective portion)	(1,093)	385
Gain (loss) reclassified accumulated OCI income (effective portion)	(429)	336
Gain (loss) recognized on derivative (ineffective portion and amount excluded from effectiveness testing)	306	248
Interest rate swap contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) recognized in OCI on derivatives (effective portion)	1,632	1,042
Interest rate swap contracts \| Interest and Foreign Exchange
Derivative Instruments, Gain (Loss) [Line Items]
Gain recognized in income on derivatives	(1)	23
Gain (loss) reclassified accumulated OCI income (effective portion)	$ (298)	$ (1,057)

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

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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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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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