Quarterly report pursuant to Section 13 or 15(d)

Guarantor Subsidiaries - Additional Information (Details)

v2.4.1.9
Guarantor Subsidiaries - Additional Information (Details) (5.625% Senior Notes, Senior Notes, USD $)
Feb. 28, 2015
Apr. 16, 2012
5.625% Senior Notes | Senior Notes
    
Guarantor Obligations [Line Items]    
Debt Instrument, Face Amount $ 300,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= atu_FivePointSixTwoFiveSeniorNotesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		$ 300,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= atu_FivePointSixTwoFiveSeniorNotesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember
Debt instrument, interest rate 5.625%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= atu_FivePointSixTwoFiveSeniorNotesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		5.625%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= atu_FivePointSixTwoFiveSeniorNotesMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember