This element represents loss contingency amount estimated recovery from third party

No definition available.

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- Definition

This element represents the amount paid to WGI from the federal government for completed and fully operational projects as well as damages and civil penalties (including doubling and trebling of damages) for violation of the statutes.

+ References

No definition available.

+ Details

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- Definition

Represents the estimated minimum cost to complete the project and promised amenities.

+ References

No definition available.

+ Details

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- Definition

Represents the number of former employees who filed wrongful termination and retaliation claims with the Department of Labor against our affiliate.

+ References

No definition available.

+ Details

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- Definition

Represents the information pertaining to number of initial public offering investors.

+ References

No definition available.

+ Details

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Namespace Prefix:	acm_
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Balance Type:	na
Period Type:	duration

- Definition

This element represents the number of the projects failure to comply with U.S. Agency for International Development (USAID) source, origin, and nationality regulations.

+ References

No definition available.

+ Details

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Namespace Prefix:	acm_
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Balance Type:	na
Period Type:	duration

- Definition

Represents the amount of securities acquired by investors

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ 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)

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-Publisher SEC

-Name Regulation S-X (SX)

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-Article 5

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

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

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- 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

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- Definition

Amount of damages paid to the plaintiff in the legal matter.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

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-Section 50

-Paragraph 9

-Subparagraph (a)

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- Definition

The value (monetary amount) of the award the plaintiff seeks in the legal matter.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

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-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)

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- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

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

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-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

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+ Details

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- Definition

Number of defendants named in a legal action.

+ References

No definition available.

+ Details

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- Definition

The estimated maximum amount of possible loss from the contingency.

+ References

+ Details

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- Definition

The estimated minimum amount of possible loss from the contingency.

+ References

+ Details

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- Definition

The difference between the maximum amount of estimated loss and the amount recorded as of the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 05

-Paragraph 5

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- Definition

The cash inflow associated with the amount received from entity's first offering of stock to the public.

+ References

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

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-Name Accounting Standards Codification

-Topic 230

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-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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Commitments and Contingencies (Details) CAD in Millions, AUD in Millions, $ in Millions				1 Months Ended		6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 06, 2014 USD ($)	Oct. 17, 2014 USD ($) project item	Jun. 17, 2014 AUD	Dec. 31, 2014 USD ($)	Jan. 31, 2010 CAD	Mar. 31, 2014 AUD	Jun. 30, 2015 USD ($) employee item	Sep. 30, 2006 AUD
Commitments and Contingencies
Securities acquired by investors \| AUD			AUD 155
URS Energy & Construction
Commitments and Contingencies
Number of former employees who filed claims against our affiliate \| employee							2
Standby Letters of Credit
Commitments and Contingencies
Contingency liability of general and professional liability insurance programs and for payment and performance guarantees							$ 411.8
USAID Egyptian Projects \| URS Corporation \| Washington Group International
Commitments and Contingencies
Number of subcontractors \| item		2
Number of projects failed to comply USAID regulations \| project		5
Amount paid to WGI from the federal government for completed and operational projects ( including doubling and trebling of damages)		$ 373.0
DOE Deactivation Demolition And Removal Project Member \| URS Corporation \| Washington Group International
Commitments and Contingencies
Projects costs, minimum							146.0
Total project costs							300.0
DOE Deactivation Demolition And Removal Project Member \| Department of Energy Member
Commitments and Contingencies
Projects costs, minimum							106.0
DOE Deactivation Demolition And Removal Project Member \| Department of Energy Member \| URS Corporation \| Washington Group International
Commitments and Contingencies
Projects costs, minimum							106.0
Projects costs, maximum							$ 146.0
Amount recovery ( including additional Fees)				$ 103.0
Minimum cost to complete the project and promised amenities				$ 100.0
Canadian Pipeline Contract Member \| URS Corporation \| Flint Energy Services Ltd
Commitments and Contingencies
Damages claimed by applicants \| CAD					CAD 85
Waste Isolation Pilot Plant Environmental Incidents Member \| URS Corporation \| Nuclear Waste Partnership LLC
Commitments and Contingencies
Civil penalty Amount	$ 17.7
AECOM Australia
Commitments and Contingencies
Proceeds from initial public offering (IPO) \| AUD								AUD 700
Bank loan \| AUD								AUD 1,400
Number of initial public offering investors \| item							770
RCM applicants
Commitments and Contingencies
Damages claimed by applicants \| AUD						AUD 1,680
Portigon AG
Commitments and Contingencies
Damages claimed by applicants \| AUD			AUD 76