Goodwill and Other Intangible Assets - Summary of changes in goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
Jun. 30, 2017	Jun. 30, 2016
Goodwill [Roll Forward]
Beginning balance	$ 67,871	$ 67,870
Acquisitions	169,071
Changes in foreign currency exchange rates	28	1
Ending balance	236,970	67,871
Human Health Segment
Goodwill [Roll Forward]
Beginning balance	66,039	66,039
Acquisitions	169,071
Changes in foreign currency exchange rates
Ending balance	235,110	66,039
Pharmaceutical Ingredients Segment
Goodwill [Roll Forward]
Beginning balance	1,651	1,650
Acquisitions
Changes in foreign currency exchange rates	23	1
Ending balance	1,674	1,651
Performance Chemicals Segment
Goodwill [Roll Forward]
Beginning balance	181	181
Acquisitions
Changes in foreign currency exchange rates	5
Ending balance	$ 186	$ 181

This element represents amount of changes in foreign currency exchange rates for goodwill of the entity.

No definition available.

Name:	acet_GoodwillChangesInForeignCurrencyExchangeRates
Namespace Prefix:	acet_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

+ Details

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

- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

+ Details

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

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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

- Details

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

- Details

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

- Details

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