Quarterly report pursuant to Section 13 or 15(d)

Fair Value of Financial Assets and Liabilities Included in Condensed Consolidated Balance Sheet (Detail)

v2.4.1.9
Fair Value of Financial Assets and Liabilities Included in Condensed Consolidated Balance Sheet (Detail) (USD $)
In Thousands, unless otherwise specified
Nov. 30, 2014
Aug. 31, 2014
Level 1 Valuation:    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Cash equivalents $ 3,042us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member 		$ 1,207us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
Investments 2,133us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member 		2,118us-gaap_InvestmentsFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member
Level 2 Valuation:    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Foreign currency derivatives $ (2,109)atu_ForeignCurrencyContractsNetAssetsLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member 		$ (966)atu_ForeignCurrencyContractsNetAssetsLiabilitiesFairValueDisclosure
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member