Represents the amount of additional earn-out payments the entity is eligible to receive after the disposal transaction.

No definition available.

Name:	aegn_DisposalGroupIncludingDiscontinuedOperationAdditionalEarnoutPayments
Namespace Prefix:	aegn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of the parent entity's interest in net assets of the subsidiary sold in the period, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	aegn_NoncontrollingInterestOwnershipPercentageSoldByParent
Namespace Prefix:	aegn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the period of time between issuance and maturity of note receivable, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	aegn_NotesReceivableTerm
Namespace Prefix:	aegn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

+ Details

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

- Definition

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6613-128477

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 30
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=116859721&loc=d3e6578-128477

+ Details

Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of consideration received or receivable for the disposal of assets and liabilities, including discontinued operation.

+ References

No definition available.

+ Details

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

- Definition

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109226348&loc=d3e2443-110228

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230

+ Details

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

- Definition

Amount of noncash consideration received for selling an asset or business through a noncash (or part noncash) transaction.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586

+ Details

Name:	us-gaap_NoncashOrPartNoncashDivestitureAmountOfConsiderationReceived1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585

+ Details

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

- Details

Name:	us-gaap_BusinessAcquisitionAxis=aegn_HebnaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=aegn_P2SMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=aegn_AegionInternationalMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=country_OM
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=aegn_CompanyJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=aegn_BayouWascoInsulationLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=aegn_BayouMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_OtherExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_NotesReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Note 1 - General (Details Textual) - USD ($) $ in Thousands			2 Months Ended	3 Months Ended	5 Months Ended	9 Months Ended
Note 1 - General (Details Textual) - USD ($) $ in Thousands	Aug. 31, 2018	Jul. 20, 2018	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	May 04, 2018
Proceeds from Divestiture of Businesses						$ 0	$ 37,942
Hebna [Member]
Business Combination, Consideration Transferred, Total			$ 3,000	$ 3,000	$ 6,000
P2S [Member]
Business Combination, Consideration Transferred, Total		$ 3,000
Aegion International [Member] \| OMAN
Business Acquisition, Percentage of Voting Interests Acquired								51.00%
Company Joint Venture [Member] \| OMAN
Business Acquisition, Percentage of Voting Interests Acquired								50.00%
Bayou Wasco Insulation, LLC [Member] \| Aegion International [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Noncontrolling Interest, Ownership Percentage Sold by Parent	51.00%
Bayou [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member]
Disposal Group, Including Discontinued Operation, Consideration	$ 46,000
Proceeds from Divestiture of Businesses	38,000
Disposal Group, Including Discontinued Operation, Additional Earn-out Payments	4,000
Bayou [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Other Expense [Member]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal				$ 8,700
Bayou [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Notes Receivable [Member]
Noncash or Part Noncash Divestiture, Amount of Consideration Received	$ 8,000
Notes Receivable, Term	2 years