XML 121 R101.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Derivatives and Hedging - Foreign Exchange Risk Management Narrative (Details) € in Millions, $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) | Dec. 31, 2016 EUR (€)
Derivative [Line Items] |  |  |  |
(Loss) income on financial instruments | $ (14.0) | $ (24.0) | $ (15.0) |
Derivatives designated as a hedge of the foreign currency exposure | $ 227.0 |  |  | € 217
Cash Flow Hedging |  |  |  |
Derivative [Line Items] |  |  |  |
Foreign currency exposures, maximum average hedging period ( in years) | 2 years |  |  |
Not Designated as Hedging Instrument |  |  |  |
Derivative [Line Items] |  |  |  |
Maximum length of time hedged in foreign currency undesignated hedge (in years) | 1 year |  |  |
Foreign exchange contracts | Not Designated as Hedging Instrument |  |  |  |
Derivative [Line Items] |  |  |  |
(Loss) income on financial instruments | $ 0.2 | $ 8.0 | $ 18.0 |

X
- Definition Maximum average contract period for foreign currency exchange rate derivatives. + References No definition available. + Details
Name: | aon_MaximumAverageMaturityOfForeignCurrencyDerivatives
Namespace Prefix: | aon_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum length of time over which the entity is hedging its exposure to the variability in future exchange rates using instruments not designated as accounting hedges. + References No definition available. + Details
Name: | aon_MaximumLengthOfTimeHedgedInForeignCurrencyUndesignatedHedge
Namespace Prefix: | aon_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (a),(c),(d),(e) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959 + Details
Name: | us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix: | us-gaap_
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_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of all derivative liabilities designated as hedges of net investment in foreign operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624163-113959 + Details
Name: | us-gaap_NetInvestmentHedgeDerivativeLiabilitiesAtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
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: |