Debt Instrument, Fair Value, Current Price

No definition available.

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- Definition

Debt Instrument, Unused Borrowing Capacity Available for Borrowing, Amount

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Interest coverage ratio

+ References

No definition available.

+ Details

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- Definition

Leverage ratio.

+ References

No definition available.

+ Details

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- Definition

Line of credit facility additional expansion option available

+ References

No definition available.

+ Details

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Period Type:	instant

- 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
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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
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Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Latest date before maturity which 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 505

-SubTopic 10

-Section 50

-Paragraph 3

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

Reference 2: 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 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_DebtInstrumentCallDateLatest
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
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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

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

+ Details

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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

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

Amount of the required periodic payments of both interest and principal.

+ References

+ Details

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

- 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

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Balance Type:	na
Period Type:	duration

- Details

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- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
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Balance Type:
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- Details

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- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
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- Details

Name:	us-gaap_DebtInstrumentAxis=atu_SeniorCreditFacilityRevolverMember
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- Details

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- Details

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Debt - Additional Information (Details)		3 Months Ended		9 Months Ended
Debt - Additional Information (Details)	Apr. 16, 2012 USD ($)	Dec. 31, 2015 USD ($)	May. 31, 2015 USD ($) covenant	May. 31, 2015 USD ($) covenant
Debt Instrument [Line Items]
Senior credit facility expansion option, available			$ 450,000,000	$ 450,000,000
Debt Instrument, actual interest rate			1.94%	1.94%
Libor Rate
Debt Instrument [Line Items]
Debt instrument, interest rate over variable rate			1.75%
Revolving Credit Facility
Debt Instrument [Line Items]
Debt Instrument, Maturity Date				May 08, 2020
Maximum borrowing capacity			$ 600,000,000	$ 600,000,000
Senior Credit Facility - Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity			300,000,000	300,000,000
Quarterly installments, payable on term loan			3,750,000
Line of Credit \| Senior Credit Facility - Revolver
Debt Instrument [Line Items]
Unused credit line			590,800,000	590,800,000
Unused credit line Available for Borrowing, Amount			250,500,000	$ 250,500,000
Senior Notes \| 5.625% Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Maturity Date				Jun. 15, 2022
Debt Instrument, Face Amount	$ 300,000,000		$ 300,000,000	$ 300,000,000
Debt instrument, interest rate	5.625%		5.625%	5.625%
Debt Instrument, Call Date, Earliest				Jun. 19, 2015
Debt Instrument, Call Date, Latest				Jul. 20, 2015
Debt Instrument, Repurchase Amount			$ 165,000,000	$ 165,000,000
Debt Instrument, Fair Value, Current Price			102.80%	102.80%
Minimum
Debt Instrument [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage			0.15%
Interest coverage ratio \| covenant			3.50	3.50
Minimum \| Libor Rate
Debt Instrument [Line Items]
Debt instrument, interest rate over variable rate			1.00%
Minimum \| Base Rate
Debt Instrument [Line Items]
Debt instrument, interest rate over variable rate			0.00%
Minimum \| Senior Notes \| 5.625% Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	100.00%
Maximum
Debt Instrument [Line Items]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage			0.35%
Leverage ratio \| covenant			3.75	3.75
Maximum \| Libor Rate
Debt Instrument [Line Items]
Debt instrument, interest rate over variable rate			2.25%
Maximum \| Base Rate
Debt Instrument [Line Items]
Debt instrument, interest rate over variable rate			1.25%
Maximum \| Senior Notes \| 5.625% Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage	102.80%
Scenario, Forecast \| Senior Credit Facility - Term Loan
Debt Instrument [Line Items]
Quarterly installments, payable on term loan		$ 7,500,000