XML 74 R54.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Acquisitions and Dispositions of Businesses - Dispositions (Details) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2016 USD ($) disposal | Dec. 31, 2015 USD ($) disposal | Dec. 31, 2014 USD ($) disposal
Dispositions |  |  |
Net gain on disposals of businesses | $ | $ 39 | $ 82 | $ 24
Disposal Group, Not Discontinued Operations |  |  |
Dispositions |  |  |
Number of dispositions | 5 | 7 | 2
Disposal Group, Not Discontinued Operations | Risk Solutions |  |  |
Dispositions |  |  |
Number of dispositions | 4 | 4 | 2
Disposal Group, Not Discontinued Operations | HR Solutions |  |  |
Dispositions |  |  |
Number of dispositions | 1 | 3 | 0

X
- Definition Represents the number of entities disposed of by the reporting entity. + References No definition available. + Details
Name: | aon_NumberOfDispositions
Namespace Prefix: | aon_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2443-110228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=64862545&loc=d3e2941-110230 + Details
Name: | us-gaap_DisposalGroupNotDiscontinuedOperationGainLossOnDisposal
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_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupNotDiscontinuedOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=aon_RiskAndInsuranceBrokerageServicesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=aon_ConsultingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |