Director & Officer Transition Charges (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017
Compensation Related Costs [Abstract]
Director & officer transition charges	$ 0	$ 0	$ 0	$ 7,784

Director & officer transition charges including compensation expense for accelerated equity vesting, severance, outplacement, legal, signing bonus and relocation costs.

No definition available.

Name:	atu_Directorofficertransitioncharges
Namespace Prefix:	atu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration