XML 45 R34.htm IDEA: XBRL DOCUMENT
v3.20.2

Share-Based Compensation Plans (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2020
Share-based Payment Arrangement [Abstract] |
Schedule of Share-Based Compensation Expense Recognized in Continuing Operations | The following table summarizes share-based compensation expense recognized in the Condensed Consolidated Statements of Income in Compensation and benefits (in millions):
| Three Months Ended September 30, |  | Nine Months Ended September 30,
| 2020 |  | 2019 |  | 2020 |  | 2019
Restricted share units (“RSUs”) | $ | 43 |  |  | $ | 42 |  |  | $ | 145 |  |  | $ | 155 |
Performance share awards (“PSAs”) | 21 |  |  | 28 |  |  | 54 |  |  | 90 |
Employee share purchase plans | 3 |  |  | 2 |  |  | 8 |  |  | 7 |
Total share-based compensation expense | $ | 67 |  |  | $ | 72 |  |  | $ | 207 |  |  | $ | 252 |
Schedule of Restricted Share Unit Activity | The following table summarizes the status of the Company’s RSUs (shares in thousands, except fair value):
| Nine Months Ended September 30,
| 2020 |  | 2019
| Shares |  | Fair Value (1) |  | Shares |  | Fair Value (1)
Non-vested at beginning of period | 3,634 |  |  | $ | 143 |  |  | 4,208 |  |  | $ | 120 |
Granted | 1,221 |  |  | $ | 185 |  |  | 1,225 |  |  | $ | 174 |
Vested | (1,316) |  |  | $ | 133 |  |  | (1,551) |  |  | $ | 112 |
Forfeited | (138) |  |  | $ | 152 |  |  | (164) |  |  | $ | 128 |
Non-vested at end of period | 3,401 |  |  | $ | 162 |  |  | 3,718 |  |  | $ | 141 |
(1)Represents per share weighted average fair value of award at date of grant.
Schedule of Performance-Based Plans | The following table summarizes the Company’s target PSAs granted and shares that would be issued at current performance levels for PSAs granted during the nine months ended September 30, 2020 and the years ended December 31, 2019 and 2018, respectively (shares in thousands and dollars in millions, except fair value):
| September 30, 2020 |  | December 31, 2019 |  | December 31, 2018
Target PSAs granted during period | 500 |  |  | 467 |  |  | 564 |
Weighted average fair value per share at date of grant | $ | 161 |  |  | $ | 165 |  |  | $ | 134 |
Number of shares that would be issued based on current performance levels | 494 |  |  | 447 |  |  | 809 |
Unamortized expense, based on current performance levels | $ | 65 |  |  | $ | 29 |  |  | $ | 8 |

X
- Definition This text block may be used to capture information pertaining to performance based plans. + References No definition available. + Details
Name: | aon_ScheduleofPerformanceBasedPlansTableTextBlock
Namespace Prefix: | aon_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Tabular disclosure of cost recognized for award under share-based payment arrangement by plan. Includes, but is not limited to, related tax benefit. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfCompensationCostForShareBasedPaymentArrangementsAllocationOfShareBasedCompensationCostsByPlanTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the changes in outstanding nonvested shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfNonvestedShareActivityTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration