XML 58 R42.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Basis of Presentation (Reclassification) (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Summary of Reclassification From Prior Period [Line Items] |  |  |
Investments | $ 135,000,000 | $ 143,000,000 |
Prepaid pension | 1,033,000,000 | 933,000,000 |
Reclassification adjustment, amount transfered from operating activities to issuance of shares for employee benefit plans in financing activities | 227,000,000 | 170,000,000 | $ 120,000,000
Reclassification adjustment, amount transfered from account payable and accrued liabilities in operating activities to financing activities |  | 85,000,000 | 62,000,000
Reclassification Adjustment, amount transfered from other assets and liabilities in operating activities to financing activities |  | 85,000,000 | 58,000,000
Purchases of shares from noncontrolling interests | (39,000,000) | 4,000,000 | (27,000,000)
Other Noncurrent Assets [Member] |  |  |
Summary of Reclassification From Prior Period [Line Items] |  |  |
Investments | $ 135,000,000 |  |
Reclassification adjustment |  | (933,000,000) |
Scenario, Previously Reported [Member] |  |  |
Summary of Reclassification From Prior Period [Line Items] |  |  |
Investments |  | 143,000,000 |
Purchases of shares from noncontrolling interests |  | 3,000,000 | (8,000,000)
Dividends paid to noncontrolling interests |  | (24,000,000) | (19,000,000)
Proceeds from sale-leaseback |  | $ 25,000,000 | $ 0

X
- Definition Prior Period Reclassification Adjustment, Amount Transfered from Account Payable and Accrued Liabilities in Operating Activities to Financing Activities + References No definition available. + Details
Name: | aon_PriorPeriodReclassificationAdjustmentAmountTransferedfromAccountPayableandAccruedLiabilitiesinOperatingActivitiestoFinancingActivities
Namespace Prefix: | aon_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Prior Period Reclassification Adjustment, Amount Transfered from Operating Activities to Issuance of Shares for Employee Benefit Plans in Financing Activities + References No definition available. + Details
Name: | aon_PriorPeriodReclassificationAdjustmentAmountTransferedfromOperatingActivitiestoIssuanceofSharesforEmployeeBenefitPlansinFinancingActivities
Namespace Prefix: | aon_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Prior Period Reclassification Adjustment, Amount Transfered from Other Assets and Liabilities in Operating Activities to Financing Activities + References No definition available. + Details
Name: | aon_PriorPeriodReclassificationAdjustmentAmountTransferedfromOtherAssetsandLiabilitiesinOperatingActivitiestoFinancingActivities
Namespace Prefix: | aon_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition [Line Items] for Summary of Reclassification From Prior Period [Table] + References No definition available. + Details
Name: | aon_SummaryofReclassificationFromPriorPeriodLineItems
Namespace Prefix: | aon_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cash outflow in the form of ordinary dividends provided by the non-wholly owned subsidiary to noncontrolling interests. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3291-108585 + Details
Name: | us-gaap_PaymentsOfDividendsMinorityInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Cumulative employer's contributions in excess of net pension cost recognized, before the adoption of the recognition provisions of FAS 158. Under FAS 158, prepaid pension costs are no longer recognized in the statement of financial position. Note that there is a separate concept for noncurrent assets relating to defined benefit pension and other defined benefit postretirement plans for use under the recognition provisions of FAS 158. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=21915240&loc=d3e1703-114919 + Details
Name: | us-gaap_PrepaidPensionCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount of a reclassification adjustment made to prior period financial statement amounts. + References No definition available. + Details
Name: | us-gaap_PriorPeriodReclassificationAdjustment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from (to) a noncontrolling interest. Excludes dividends paid to the noncontrolling interest. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3291-108585 + Details
Name: | us-gaap_ProceedsFromPaymentsToMinorityShareholders
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow after closing and deferred financing costs received by a seller-lessee in a sale-leaseback recognized in financing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 40 -Section 55 -Paragraph 51 -URI http://asc.fasb.org/extlink&oid=28365400&loc=d3e51840-112757 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 40 -Section 55 -Paragraph 50 -URI http://asc.fasb.org/extlink&oid=28365400&loc=d3e51831-112757 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 40 -Section 55 -Paragraph 52 -URI http://asc.fasb.org/extlink&oid=28365400&loc=d3e51843-112757 + Details
Name: | us-gaap_SaleLeasebackTransactionNetProceedsFinancingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ScenarioPreviouslyReportedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |