XML 76 R57.htm IDEA: XBRL DOCUMENT v3.21.2

Revenue Recognition - Disaggregated revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Revenue Recognition
Total revenue	$ 13,340.9	$ 13,240.0	$ 13,642.5
Cost reimbursable
Revenue Recognition
Total revenue	5,319.4	5,734.5	5,958.2
Guaranteed maximum price
Revenue Recognition
Total revenue	4,582.7	3,896.8	3,962.6
Fixed price
Revenue Recognition
Total revenue	3,438.8	3,608.7	3,721.7
Americas
Revenue Recognition
Total revenue	10,228.3	10,138.3	10,390.8
Europe, Middle East, Africa
Revenue Recognition
Total revenue	1,588.1	1,620.3	1,752.1
Asia Pacific
Revenue Recognition
Total revenue	$ 1,524.5	$ 1,481.4	$ 1,499.6

X

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

No definition available.

+ Details

Name:	acm_RevenueFromContractWithCustomerExcludingTaxAssessed
Namespace Prefix:	acm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- 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

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

X

- Details

Name:	us-gaap_ContractWithCustomerBasisOfPricingAxis=acm_CostReimbursableContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ContractWithCustomerBasisOfPricingAxis=acm_GuaranteedMaximumPriceContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ContractWithCustomerBasisOfPricingAxis=us-gaap_FixedPriceContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	srt_StatementGeographicalAxis=us-gaap_EMEAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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