XML 57 R34.htm IDEA: XBRL DOCUMENT
v2.4.0.6

Basis of Presentation (Details) | 6 Months Ended
--- | ---
Mar. 31, 2013
Minimum |
Length of fiscal year | 364 days
Maximum |
Length of fiscal year | 371 days

X
- Definition Represents the length of fiscal years of the company. + References No definition available. + Details
Name: | acm_LengthOfFiscalYear
Namespace Prefix: | acm_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration