XML 41 R35.htm IDEA: XBRL DOCUMENT v2.4.1.9

Basis of Presentation (Details)	3 Months Ended	6 Months Ended
	Mar. 31, 2015 segment	Mar. 31, 2015 segment
Number of reportable segments	3us-gaap_NumberOfReportableSegments	3us-gaap_NumberOfReportableSegments
Minimum
Number of reportable segments		2us-gaap_NumberOfReportableSegments / us-gaap_RangeAxis = us-gaap_MinimumMember
Length of fiscal year		364 days
Maximum
Number of reportable segments		3us-gaap_NumberOfReportableSegments / us-gaap_RangeAxis = us-gaap_MaximumMember
Length of fiscal year		371 days

X

- Definition

Represents the length of fiscal year of the company in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	acm_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: