Quarterly report pursuant to Section 13 or 15(d)

Derivatives Narrative (Details)

v2.4.1.9
Derivatives Narrative (Details) (USD $)
 3 Months Ended 6 Months Ended
Feb. 28, 2015
Feb. 28, 2014
Feb. 28, 2015
Feb. 28, 2014
Aug. 31, 2014
Derivative [Line Items]          
Gain (Loss) on Foreign Currency Fair Value Hedge Derivatives and Not Designated as Hedging Instruments at Fair Value $ 55,000atu_GainLossOnForeignCurrencyFairValueHedgeDerivativesAndNotDesignatedAsHedgingInstrumentsAtFairValue $ (2,619,000)atu_GainLossOnForeignCurrencyFairValueHedgeDerivativesAndNotDesignatedAsHedgingInstrumentsAtFairValue $ (2,006,000)atu_GainLossOnForeignCurrencyFairValueHedgeDerivativesAndNotDesignatedAsHedgingInstrumentsAtFairValue $ (11,310,000)atu_GainLossOnForeignCurrencyFairValueHedgeDerivativesAndNotDesignatedAsHedgingInstrumentsAtFairValue  
Fair Value Hedging [Member]          
Derivative [Line Items]          
Derivative, Notional Amount $ 191,500,000invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_FairValueHedgingMember 		  $ 191,500,000invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_FairValueHedgingMember 		  $ 219,900,000invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_FairValueHedgingMember