Represents number of debt instrument installments.

No definition available.

Name:	acet_DebtInstrumentNumberOfInstallments
Namespace Prefix:	acet_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents increase of future maximum borrowing capacity.

+ References

No definition available.

+ Details

Name:	acet_LineOfCreditFacilityMaximumFutureBorrowingCapacityIncrease
Namespace Prefix:	acet_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the number of banks.

+ References

No definition available.

+ Details

Name:	acet_NumberOfBanks
Namespace Prefix:	acet_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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+ Details

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

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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+ Details

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

- 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

Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDateDescription
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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

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, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
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+ Details

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

- Details

Name:	us-gaap_TypeOfArrangementAxis=acet_AmendedCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
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Period Type:

Debt (Narrative) (Detail 1) $ in Thousands	1 Months Ended	3 Months Ended
Debt (Narrative) (Detail 1) $ in Thousands	Dec. 21, 2016 USD ($) Entity	Sep. 30, 2018 USD ($) Installment	Jun. 30, 2018 USD ($)	Aug. 26, 2016 USD ($)
Debt Instrument [Line Items]
Borrowed loans		$ 315,382	$ 317,398
Second Amended and Restated Credit Agreement (the "A&R Credit Agreement")
Debt Instrument [Line Items]
Number of banks \| Entity	11
Revolving Bank Loans
Debt Instrument [Line Items]
Borrowed loans		$ 62,000	62,000
Revolving Bank Loans \| Second Amended and Restated Credit Agreement (the "A&R Credit Agreement")
Debt Instrument [Line Items]
Aggregate revolving commitment	$ 225,000			$ 150,000
Maturity date description	Maturity Date shall mean the date that is 91 days prior to the 2015 Convertible Maturity Date
Revolving Bank Loans \| Second Amended and Restated Credit Agreement (the "A&R Credit Agreement") \| Eurodollar Loan \| Minimum
Debt Instrument [Line Items]
Debt interest rate		5.00%
Revolving Bank Loans \| Second Amended and Restated Credit Agreement (the "A&R Credit Agreement") \| Eurodollar Loan \| Maximum
Debt Instrument [Line Items]
Debt interest rate		5.02%
Initial Term Loan
Debt Instrument [Line Items]
Borrowed loans		$ 121,392	$ 124,959
Number of installments \| Installment		19
Frequency of periodic payment		Quarterly
Principal payment		$ 3,750
Initial Term Loan \| Second Amended and Restated Credit Agreement (the "A&R Credit Agreement")
Debt Instrument [Line Items]
Borrowed loans		150,000
Aggregate amount increase		100,000
Remaining amount outstanding		$ 123,750
Initial Term Loan \| Second Amended and Restated Credit Agreement (the "A&R Credit Agreement") \| Eurodollar Loan
Debt Instrument [Line Items]
Debt interest rate		9.39%