XML 51 R36.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Goodwill and Other Intangible Assets (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract] |
Schedule of changes in the net carrying amount of goodwill by operating segment | The changes in the net carrying amount of goodwill for the years ended December 31, 2018 and 2017, respectively, are as follows (in millions):
Balance as of January 1, 2017 | $ | 7,410 |
Goodwill related to current year acquisitions | 619 |
Goodwill related to disposals | (5 | )
Goodwill related to prior year acquisitions | (13 | )
Foreign currency translation | 347 |
Balance as of December 31, 2017 | $ | 8,358 |
Goodwill related to current year acquisitions | 38 |
Goodwill related to disposals | (2 | )
Goodwill related to prior year acquisitions | 4 |
Foreign currency translation | (227 | )
Balance as of December 31, 2018 | $ | 8,171 |
Schedule of other intangible assets by asset class | Amortization basis and estimated useful lives by intangible asset type are generally as follows:
Intangible Asset Description |  | Amortization Basis |  | Expected Life
Customer-related and contract-based |  | In line with underlying cash flows |  | 7 to 20 years
Tradenames |  | Straight-line |  | 1 to 3 years
Technology and other |  | Straight-line |  | 5 to 7 years
Other intangible assets by asset class are as follows (in millions):
| As of December 31
| 2018 |  | 2017
| Gross Carrying Amount |  | Accumulated Amortization and Impairment |  | Net Carrying Amount |  | Gross Carrying Amount |  | Accumulated Amortization and Impairment |  | Net Carrying Amount
Customer related and contract based | 2,240 |  |  | 1,444 |  |  | 796 |  |  | 2,550 |  |  | 1,415 |  |  | 1,135 |
Tradenames | 1,027 |  |  | 740 |  |  | 287 |  |  | 1,047 |  |  | 533 |  |  | 514 |
Technology and other | 391 |  |  | 325 |  |  | 66 |  |  | 416 |  |  | 332 |  |  | 84 |
Total | $ | 3,658 |  |  | $ | 2,509 |  |  | $ | 1,149 |  |  | $ | 4,013 |  |  | $ | 2,280 |  |  | $ | 1,733 |
Schedule of estimated future amortization expense on intangible assets | The estimated future amortization for finite-lived intangible assets as of December 31, 2018 is as follows (in millions):
|  | Estimated Future Amortization
For the years ended |
2019 |  | $ | 385 |
2020 |  | 219 |
2021 |  | 126 |
2022 |  | 84 |
2023 |  | 72 |
Thereafter |  | 263 |
Total |  | $ | 1,149 |

X
- Definition Tabular disclosure of the class of other intangible assets, which includes finite and indefinite-lived intangible assets. + References No definition available. + Details
Name: | aon_ScheduleOfFiniteAndIndefiniteLivedIntangibleAssetsTableTextBlock
Namespace Prefix: | aon_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13854-109267 + Details
Name: | us-gaap_ScheduleOfGoodwillTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the amount of amortization expense expected to be recorded in succeeding fiscal years for finite-lived intangible assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
Name: | us-gaap_ScheduleofFiniteLivedIntangibleAssetsFutureAmortizationExpenseTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration