XML 66 R54.htm IDEA: XBRL DOCUMENT v3.8.0.1

Derivative Financial Instruments and Fair Value Measurements - Cash Flow Hedges (Details) - Designated as Hedging Instrument - Cash Flow Hedging AUD in Millions, $ in Millions	Dec. 31, 2017 AUD	Dec. 31, 2017 USD ($)	Sep. 30, 2017 AUD	Sep. 30, 2017 USD ($)
Interest Rate Swap June 2018
Derivative financial instruments
Notional Amount		$ 300.0		$ 300.0
Fixed Rate (as a percent)	1.63%	1.63%	1.63%	1.63%
Interest Rate Swap September 2018
Derivative financial instruments
Notional Amount		$ 300.0		$ 300.0
Fixed Rate (as a percent)	1.54%	1.54%	1.54%	1.54%
Foreign currency contracts
Derivative financial instruments
Notional principal of derivative exchange contracts	AUD 13.2	$ 9.9	AUD 15.1	$ 11.3

X

- Definition

Aggregate notional amount of foreign currency derivatives to exchange foreign currencies. Notional amount refers to the number of currency units specified in the foreign currency derivative contract.

+ References

No definition available.

+ Details

Name:	acm_NotionalAmountOfForeignCurrencyDerivativeExchangeContracts
Namespace Prefix:	acm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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

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

X

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=acm_InterestRateSwapJune2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=acm_InterestRateSwapSeptember2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: