Debt Instrument, Repurchase Amount Available in tender offer

No definition available.

Name:	atu_DebtInstrumentRepurchaseAmountAvailable
Namespace Prefix:	atu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Debt Instrument, Unused Borrowing Capacity Available for Borrowing, Amount

+ References

No definition available.

+ Details

Name:	atu_DebtInstrumentUnusedBorrowingCapacityAvailableforBorrowingAmount
Namespace Prefix:	atu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Debt Redemption Price As Percentage Of Principal

+ References

No definition available.

+ Details

Name:	atu_DebtRedemptionPriceAsPercentageOfPrincipal
Namespace Prefix:	atu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fixed charge coverage ratio.

+ References

No definition available.

+ Details

Name:	atu_FixedChargeCoverageRatio
Namespace Prefix:	atu_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Leverage ratio.

+ References

No definition available.

+ Details

Name:	atu_LeverageRatio
Namespace Prefix:	atu_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of credit facility additional expansion option available

+ References

No definition available.

+ Details

Name:	atu_LineOfCreditFacilityAdditionalExpansionOptionAvailable
Namespace Prefix:	atu_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility, Number of Financial Covenants

+ References

No definition available.

+ Details

Name:	atu_LineofCreditFacilityNumberofFinancialCovenants
Namespace Prefix:	atu_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Earliest date before maturity when the issuer can call the outstanding debt instrument for repayment or conversion to equity, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

+ Details

Name:	us-gaap_DebtInstrumentCallDateEarliest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the required periodic payments applied to principal.

+ References

+ Details

Name:	us-gaap_DebtInstrumentPeriodicPaymentPrincipal
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

+ Details

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

- Definition

Amount of unused borrowing capacity under the long-term financing arrangement that is available to the entity as of the balance sheet date.

+ References

+ Details

Name:	us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of cash paid for interest during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=atu_FivePointSixTwoFiveSeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=atu_SeniorCreditFacilityTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=atu_SeniorCreditFacilityRevolverMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=atu_SeniorCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_BaseRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	atu_PeriodAxis=atu_PeriodOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	atu_PeriodAxis=atu_PeriodThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Additional Information (Detail) $ in Millions			3 Months Ended	12 Months Ended
Debt - Additional Information (Detail) $ in Millions	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Aug. 31, 2015 USD ($)	Aug. 31, 2015 USD ($) covenant	Aug. 31, 2014 USD ($)	Aug. 31, 2013 USD ($)	Jul. 19, 2015 USD ($)	Jun. 19, 2015 USD ($)	Apr. 16, 2012 USD ($)
Debt Instrument [Line Items]
Cash interest payments				$ 24.8	$ 21.0	$ 21.0
5.625% Senior Notes \| Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Maturity Date				Jun. 15, 2022
Face amount									$ 300.0
Debt instrument, interest rate			5.625%	5.625%		5.625%			5.625%
Minimum \| 5.625% Senior Notes \| Senior Notes
Debt Instrument [Line Items]
Debt Redemption Price As Percentage Of Principal									100.00%
Maximum \| 5.625% Senior Notes \| Senior Notes
Debt Instrument [Line Items]
Debt Redemption Price As Percentage Of Principal									102.80%
Debt Instrument, Call Date, Earliest			Jun. 19, 2015
Debt Instrument, Repurchase Amount Available								$ 165.0
Debt Instrument, Repurchase Amount							$ 11.9
Senior Credit Facility - Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 300.0	$ 300.0
Senior Credit Facility - Revolver
Debt Instrument [Line Items]
Debt Instrument, Maturity Date				May 08, 2020
Maximum borrowing capacity			600.0	$ 600.0
Unused credit line			589.0	589.0
Unused Borrowing Capacity Available for Borrowing			$ 176.0	176.0
Senior Credit Facility - Revolver \| Minimum
Debt Instrument [Line Items]
Percentage of non-use fee, annually			0.15%
Senior Credit Facility - Revolver \| Maximum
Debt Instrument [Line Items]
Percentage of non-use fee, annually			0.35%
Senior Credit Facility
Debt Instrument [Line Items]
Senior credit facility expansion option, available			$ 450.0	$ 450.0
Number of financial covenants \| covenant				2
Senior Credit Facility \| Minimum
Debt Instrument [Line Items]
Fixed charge coverage ratio			3.50	3.50
Senior Credit Facility \| Maximum
Debt Instrument [Line Items]
Leverage ratio			3.75	3.75
Senior Credit Facility \| LIBOR
Debt Instrument [Line Items]
Debt instrument interest rate over variable rate				1.75%
Debt instrument actual interest rate			2.00%	2.00%
Senior Credit Facility \| LIBOR \| Minimum
Debt Instrument [Line Items]
Debt instrument interest rate over variable rate				1.00%
Senior Credit Facility \| LIBOR \| Maximum
Debt Instrument [Line Items]
Debt instrument interest rate over variable rate				2.25%
Senior Credit Facility \| Base Rate \| Minimum
Debt Instrument [Line Items]
Debt instrument interest rate over variable rate				0.00%
Senior Credit Facility \| Base Rate \| Maximum
Debt Instrument [Line Items]
Debt instrument interest rate over variable rate				1.25%
Scenario, Forecast \| Senior Credit Facility - Term Loan \| Starting on June 30, 2016
Debt Instrument [Line Items]
Quarterly installments, payable on term loan		$ 3.8
Scenario, Forecast \| Senior Credit Facility - Term Loan \| Starting on June 30, 2017
Debt Instrument [Line Items]
Quarterly installments, payable on term loan	$ 7.5