XML 69 R54.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Restructuring - Schedule of Restructuring and Related Expenses (Details) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2017 USD ($) | Jun. 30, 2017 USD ($)
Restructuring Cost and Reserve [Line Items] |  |
Estimated Remaining Costs | $ 451 | $ 451
2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 155 | 299
Expected total cost | 750 | 750
Workforce reduction | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 102 | 205
Estimated Remaining Costs | 98 | 98
Expected total cost | 303 | 303
Technology rationalization | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 7 | 10
Estimated Remaining Costs | 136 | 136
Expected total cost | 146 | 146
Expected contract termination cost remaining | 9 | 9
Lease consolidation | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 1 | 4
Estimated Remaining Costs | 76 | 76
Expected total cost | 80 | 80
Contract termination costs incurred | 1 | 5
Expected contract termination cost remaining | 80 | 80
Asset impairments | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 11 | 24
Estimated Remaining Costs | 16 | 16
Expected total cost | 40 | 40
Other Restructuring | 2017 Plan |  |
Restructuring Cost and Reserve [Line Items] |  |
Costs incurred | 34 | 56
Estimated Remaining Costs | 125 | 125
Expected total cost | $ 181 | $ 181

X
- Definition Restructuring and Related Cost, Expected Contract Termination Cost Remaining + References No definition available. + Details
Name: | aon_RestructuringandRelatedCostExpectedContractTerminationCostRemaining
Namespace Prefix: | aon_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Restructuring and Related Cost, Incurred Contract Termination Costs + References No definition available. + Details
Name: | aon_RestructuringandRelatedCostIncurredContractTerminationCosts
Namespace Prefix: | aon_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount expected to be recognized in earnings for the specified restructuring cost. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4(b)) -URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747 + Details
Name: | us-gaap_RestructuringAndRelatedCostExpectedCost1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of expected cost remaining for the specified restructuring cost. + References No definition available. + Details
Name: | us-gaap_RestructuringAndRelatedCostExpectedCostRemaining1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB Topic 5.P.4(b)) -URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747 + Details
Name: | us-gaap_RestructuringAndRelatedCostIncurredCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_RestructuringCostAndReserveLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RestructuringPlanAxis=aon_A2017PlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=aon_TechnologyRationalizationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=aon_RealEstateRealizationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=aon_AssetImpairmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringCostAndReserveAxis=us-gaap_OtherRestructuringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |