Summary of Financial Information by Reportable Segment and Product Line (Details) $ in Thousands	3 Months Ended
Nov. 30, 2017 USD ($) Segment	Nov. 30, 2016 USD ($)	Aug. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| Segment	3
Net sales	$ 288,955	$ 265,793
Operating profit (Loss)	14,673	8,471
Assets	1,490,241		$ 1,516,955
Industrial Tools [Member]
Segment Reporting Information [Line Items]
Net sales	84,510	79,039
Industrial
Segment Reporting Information [Line Items]
Net sales	96,916	87,290
Operating profit (Loss)	18,243	18,776
Assets	314,215		329,134
Heavy Lifting Technology [Member]
Segment Reporting Information [Line Items]
Net sales	12,406	8,251
Energy
Segment Reporting Information [Line Items]
Net sales	75,841	84,646
Operating profit (Loss)	293	3,210
Assets	480,402		482,963
Energy Maintenance & Integrity
Segment Reporting Information [Line Items]
Net sales	56,710	64,821
Other Energy Solutions [Member]
Segment Reporting Information [Line Items]
Net sales	19,131	19,825
Engineered Solutions
Segment Reporting Information [Line Items]
Net sales	116,198	93,857
Operating profit (Loss)	6,334	755
Assets	539,978		531,068
On-Highway
Segment Reporting Information [Line Items]
Net sales	64,882	51,630
Agriculture, Off-Highway and Other
Segment Reporting Information [Line Items]
Net sales	51,316	42,227
General Corporate
Segment Reporting Information [Line Items]
Operating profit (Loss)	(10,197)	$ (14,270)
Assets	$ 155,646		$ 173,790

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(12))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(11))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_Assets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_SalesRevenueNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_IndustrialToolsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_IndustrialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_HeavyLiftingTechnologyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_EnergyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_EnergyMaintenanceIntegrityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_OtherEnergySolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_EngineeredSolutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_OnHighwayMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_AgricultureOffHighwayandOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=atu_GeneralCoporateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: