XML 58 R2.htm IDEA: XBRL DOCUMENT
v3.23.1

Pay vs Performance Disclosure | 12 Months Ended
--- | ---
Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($)
Pay vs Performance Disclosure [Table] |  |  |
Pay vs Performance [Table Text Block] | Pay vs. Performance As described in the Compensation Discussion & Analysis (“CD&A”), Aon has a strong pay for performance philosophy that shapes how we deliver compensation to all colleagues, including the senior executives of the firm. This is evidenced by (1) the weighting of fixed vs variable compensation awarded annually, (2) the proportion of variable compensation delivered in the form of company equity instruments, and (3) the proportion of equity awards that are leveraged on performance conditions above and beyond share price. 2022 Compensation Details Variable compensation awarded to the CEO and other NEOs (on average) represented 92% and 81%, respectively, of the total compensation awarded for 2022. To maximize shareholder alignment, 100% of their variable compensation was delivered in the form of equity, including the annual incentive for the year. Finally, 100% and 89%, respectively, of the equity compensation for the CEO and other NEOs (on average) is comprised of performance share units (“PSU”) under our Leadership Performance Program (“LPP”) that can result in a 0x – 2x payout based on performance against Adjusted EPS goals which we believe closely aligns with shareholder value creation. PVP Disclosure In accordance with rules adopted by the Securities and Exchange Commission pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, we provide the following disclosure regarding executive compensation covering calculations and narrative of Compensation Actually Paid (“CAP”) under new SEC Pay Versus Performance (“PVP”) disclosure requirements for our principal executive officer (“PEO”) and Non-PEO NEOs and Company performance for the fiscal years listed below. The Compensation Committee did not consider the pay versus performance disclosure below in making its pay decisions for any of the years shown.
Year |  | Summary Compensation Table Total for PEO 1 ($) |  |  | CAP to PEO 1,2 ($) |  |  | Average Summary Compensation Table Total for Non-PEO NEOs 1 ($) |  |  | Average CAP Paid to Non-PEO NEOs 1,2 ($) |  |  | Value of Initial Fixed $100 Investment based on: 3 |  |  | Net Income ($ Millions) |  |  | Adjusted Earnings per Share Growth 4 |
| TSR ($) |  |  | Peer Group TSR ($) |
2022 |  |  | 19,668,985 |  |  |  | 18,597,824 |  |  |  | 6,643,617 |  |  |  | 6,468,548 |  |  |  | 148 |  |  |  | 119 |  |  |  | 2,589 |  |  |  | 12 | %
2021 |  |  | 19,868,384 |  |  |  | 100,549,260 |  |  |  | 7,644,425 |  |  |  | 25,579,739 |  |  |  | 147 |  |  |  | 133 |  |  |  | 1,308 |  |  |  | 22 | %
2020 |  |  | 20,294,496 |  |  |  | 39,382,835 |  |  |  | 6,898,103 |  |  |  | 11,457,219 |  |  |  | 102 |  |  |  | 98 |  |  |  | 2,018 |  |  |  | 7 | %
1. | The principal executive officer (PEO) for each year reflected in the table is Gregory C. Case, the Company’s Chief Executive Officer. The non-PEO NEOs are Christa Davies, Eric Andersen, Lisa Stevens (for years 2021 and 2022 only), Darren Zeidel (for years 2021 and 2022 only), John Bruno (for 2020 only) and Anthony Goland (for 2020 only).
2. | The amounts shown for CAP have been calculated in accordance with Item 402(v) of Regulation S-K and do not reflect compensation actually earned, realized, or received by the Company’s NEOs. CAP amounts reflect the Summary Compensation Table Total with exclusions and inclusions of certain amounts for the PEO and the Non-PEO NEOs as set forth below. Equity values are calculated in accordance with FASB ASC Topic 718. Amounts in the Exclusion of Stock Awards column are the totals from the Stock Awards column set forth in the Summary Compensation Table.
PEO
Year |  | Summary Compensation Table Total for PEO |  |  | Exclusion of Stock Awards for PEO |  |  | Inclusion of Equity Values for PEO |  |  | CAP to PEO |
2022 |  |  | 19,668,985 |  |  |  | (17,497,455 | ) |  |  | 16,426,294 |  |  |  | 18,597,824 |
2021 |  |  | 19,868,384 |  |  |  | (15,262,436 | ) |  |  | 95,943,312 |  |  |  | 100,549,260 |
2020 |  |  | 20,294,496 |  |  |  | (15,880,566 | ) |  |  | 34,968,905 |  |  |  | 39,382,835 |
Average Non-PEO NEOs
Year |  | Average Summary Compensation Table Total for Non-PEO NEOs |  |  | Average Exclusion of Change in Pension Value for Non-PEO NEOs |  |  | Average Exclusion of Stock Awards for Non-PEO NEOs |  |  | Average Inclusion of Equity Values for Non-PEO NEOs |  |  | Average CAP to Non-PEO NEOs |
2022 |  |  | 6,643,617 |  |  |  | — |  |  |  | (4,729,173 | ) |  |  | 4,554,104 |  |  |  | 6,468,548 |
2021 |  |  | 7,644,425 |  |  |  | — |  |  |  | (4,583,837 | ) |  |  | 22,519,151 |  |  |  | 25,579,739 |
2020 |  |  | 6,898,103 |  |  |  | (76,821 | ) |  |  | (4,387,596 | ) |  |  | 9,023,533 |  |  |  | 11,457,219 |
The amounts in the Inclusion of Equity Values in the tables above are derived from the amounts set forth in the following tables: PEO
Year |  | Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for PEO |  |  | Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for PEO |  |  | Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for PEO |  |  | Value of Dividends or Other Earnings Paid on Equity Awards Not Otherwise Included for PEO |  |  | Total - Inclusion of Equity Values for PEO |
2022 |  |  | 16,554,822 |  |  |  | (52,980 | ) |  |  | (83,279 | ) |  |  | 7,731 |  |  |  | 16,426,294 |
2021 |  |  | 39,121,312 |  |  |  | 38,650,509 |  |  |  | 18,164,704 |  |  |  | 6,787 |  |  |  | 95,943,312 |
2020 |  |  | 20,945,730 |  |  |  | 12,672,451 |  |  |  | 1,339,915 |  |  |  | 10,809 |  |  |  | 34,968,905 |
Average Non-PEO NEOs
Year |  | Average Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for Non-PEO NEOs |  |  | Average Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for Non-PEO NEOs |  |  | Average Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for Non-PEO NEOs |  |  | Average Value of Dividends or Other Earnings Paid on Equity Awards Not Otherwise Included for Non-PEO NEOs |  |  | Total - Average Inclusion of Equity Values for Non-PEO NEOs |
2022 |  |  | 4,599,376 |  |  |  | (15,750 | ) |  |  | (37,513 | ) |  |  | 7,991 |  |  |  | 4,554,104 |
2021 |  |  | 11,411,916 |  |  |  | 8,245,180 |  |  |  | 2,859,048 |  |  |  | 3,007 |  |  |  | 22,519,151 |
2020 |  |  | 5,771,045 |  |  |  | 2,890,055 |  |  |  | 357,014 |  |  |  | 5,419 |  |  |  | 9,023,533 |
3. | The Peer Group TSR set forth in this table utilizes the S&P 500 Financials Index, which we also utilize in the stock performance graph required by Item 201(e) of Regulation S-K included in our Annual Report for the year ended December 31, 2022. The comparison assumes $100 was invested for the period starting December 31, 2019, through the end of the listed year in the Company and in the S&P 500 Financials Index, respectively. Historical stock performance is not necessarily indicative of future stock performance.
4. | We determined Adjusted EPS to be the most important financial performance measure used to link Company performance to CAP to our PEO and Non-PEO NEOs in 2022. This performance measure may not have been the most important financial performance measure for years 2021 and 2020 and we may determine a different financial performance measure to be the most important financial performance measure in future years.
Company Selected Measure Name | Adjusted EPS |  |
Named Executive Officers, Footnote [Text Block] |
1. | The principal executive officer (PEO) for each year reflected in the table is Gregory C. Case, the Company’s Chief Executive Officer. The non-PEO NEOs are Christa Davies, Eric Andersen, Lisa Stevens (for years 2021 and 2022 only), Darren Zeidel (for years 2021 and 2022 only), John Bruno (for 2020 only) and Anthony Goland (for 2020 only).
Peer Group Issuers, Footnote [Text Block] | The Peer Group TSR set forth in this table utilizes the S&P 500 Financials Index, which we also utilize in the stock performance graph required by Item 201(e) of Regulation S-K included in our Annual Report for the year ended December 31, 2022. The comparison assumes $100 was invested for the period starting December 31, 2019, through the end of the listed year in the Company and in the S&P 500 Financials Index, respectively. Historical stock performance is not necessarily indicative of future stock performance. |  |
PEO Total Compensation Amount | $ 19,668,985 | $ 19,868,384 | $ 20,294,496
PEO Actually Paid Compensation Amount | $ 18,597,824 | 100,549,260 | 39,382,835
Adjustment To PEO Compensation, Footnote [Text Block] | PEO
Year |  | Summary Compensation Table Total for PEO |  |  | Exclusion of Stock Awards for PEO |  |  | Inclusion of Equity Values for PEO |  |  | CAP to PEO |
2022 |  |  | 19,668,985 |  |  |  | (17,497,455 | ) |  |  | 16,426,294 |  |  |  | 18,597,824 |
2021 |  |  | 19,868,384 |  |  |  | (15,262,436 | ) |  |  | 95,943,312 |  |  |  | 100,549,260 |
2020 |  |  | 20,294,496 |  |  |  | (15,880,566 | ) |  |  | 34,968,905 |  |  |  | 39,382,835 |
Average Non-PEO NEOs
Year |  | Average Summary Compensation Table Total for Non-PEO NEOs |  |  | Average Exclusion of Change in Pension Value for Non-PEO NEOs |  |  | Average Exclusion of Stock Awards for Non-PEO NEOs |  |  | Average Inclusion of Equity Values for Non-PEO NEOs |  |  | Average CAP to Non-PEO NEOs |
2022 |  |  | 6,643,617 |  |  |  | — |  |  |  | (4,729,173 | ) |  |  | 4,554,104 |  |  |  | 6,468,548 |
2021 |  |  | 7,644,425 |  |  |  | — |  |  |  | (4,583,837 | ) |  |  | 22,519,151 |  |  |  | 25,579,739 |
2020 |  |  | 6,898,103 |  |  |  | (76,821 | ) |  |  | (4,387,596 | ) |  |  | 9,023,533 |  |  |  | 11,457,219 |
The amounts in the Inclusion of Equity Values in the tables above are derived from the amounts set forth in the following tables: PEO
Year |  | Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for PEO |  |  | Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for PEO |  |  | Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for PEO |  |  | Value of Dividends or Other Earnings Paid on Equity Awards Not Otherwise Included for PEO |  |  | Total - Inclusion of Equity Values for PEO |
2022 |  |  | 16,554,822 |  |  |  | (52,980 | ) |  |  | (83,279 | ) |  |  | 7,731 |  |  |  | 16,426,294 |
2021 |  |  | 39,121,312 |  |  |  | 38,650,509 |  |  |  | 18,164,704 |  |  |  | 6,787 |  |  |  | 95,943,312 |
2020 |  |  | 20,945,730 |  |  |  | 12,672,451 |  |  |  | 1,339,915 |  |  |  | 10,809 |  |  |  | 34,968,905 |
Average Non-PEO NEOs
Year |  | Average Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for Non-PEO NEOs |  |  | Average Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for Non-PEO NEOs |  |  | Average Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for Non-PEO NEOs |  |  | Average Value of Dividends or Other Earnings Paid on Equity Awards Not Otherwise Included for Non-PEO NEOs |  |  | Total - Average Inclusion of Equity Values for Non-PEO NEOs |
2022 |  |  | 4,599,376 |  |  |  | (15,750 | ) |  |  | (37,513 | ) |  |  | 7,991 |  |  |  | 4,554,104 |
2021 |  |  | 11,411,916 |  |  |  | 8,245,180 |  |  |  | 2,859,048 |  |  |  | 3,007 |  |  |  | 22,519,151 |
2020 |  |  | 5,771,045 |  |  |  | 2,890,055 |  |  |  | 357,014 |  |  |  | 5,419 |  |  |  | 9,023,533 |
Non-PEO NEO Average Total Compensation Amount | $ 6,643,617 | 7,644,425 | 6,898,103
Non-PEO NEO Average Compensation Actually Paid Amount | $ 6,468,548 | 25,579,739 | 11,457,219
Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | PEO
Year |  | Summary Compensation Table Total for PEO |  |  | Exclusion of Stock Awards for PEO |  |  | Inclusion of Equity Values for PEO |  |  | CAP to PEO |
2022 |  |  | 19,668,985 |  |  |  | (17,497,455 | ) |  |  | 16,426,294 |  |  |  | 18,597,824 |
2021 |  |  | 19,868,384 |  |  |  | (15,262,436 | ) |  |  | 95,943,312 |  |  |  | 100,549,260 |
2020 |  |  | 20,294,496 |  |  |  | (15,880,566 | ) |  |  | 34,968,905 |  |  |  | 39,382,835 |
Average Non-PEO NEOs
Year |  | Average Summary Compensation Table Total for Non-PEO NEOs |  |  | Average Exclusion of Change in Pension Value for Non-PEO NEOs |  |  | Average Exclusion of Stock Awards for Non-PEO NEOs |  |  | Average Inclusion of Equity Values for Non-PEO NEOs |  |  | Average CAP to Non-PEO NEOs |
2022 |  |  | 6,643,617 |  |  |  | — |  |  |  | (4,729,173 | ) |  |  | 4,554,104 |  |  |  | 6,468,548 |
2021 |  |  | 7,644,425 |  |  |  | — |  |  |  | (4,583,837 | ) |  |  | 22,519,151 |  |  |  | 25,579,739 |
2020 |  |  | 6,898,103 |  |  |  | (76,821 | ) |  |  | (4,387,596 | ) |  |  | 9,023,533 |  |  |  | 11,457,219 |
The amounts in the Inclusion of Equity Values in the tables above are derived from the amounts set forth in the following tables: PEO
Year |  | Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for PEO |  |  | Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for PEO |  |  | Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for PEO |  |  | Value of Dividends or Other Earnings Paid on Equity Awards Not Otherwise Included for PEO |  |  | Total - Inclusion of Equity Values for PEO |
2022 |  |  | 16,554,822 |  |  |  | (52,980 | ) |  |  | (83,279 | ) |  |  | 7,731 |  |  |  | 16,426,294 |
2021 |  |  | 39,121,312 |  |  |  | 38,650,509 |  |  |  | 18,164,704 |  |  |  | 6,787 |  |  |  | 95,943,312 |
2020 |  |  | 20,945,730 |  |  |  | 12,672,451 |  |  |  | 1,339,915 |  |  |  | 10,809 |  |  |  | 34,968,905 |
Average Non-PEO NEOs
Year |  | Average Year-End Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year for Non-PEO NEOs |  |  | Average Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards for Non-PEO NEOs |  |  | Average Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year for Non-PEO NEOs |  |  | Average Value of Dividends or Other Earnings Paid on Equity Awards Not Otherwise Included for Non-PEO NEOs |  |  | Total - Average Inclusion of Equity Values for Non-PEO NEOs |
2022 |  |  | 4,599,376 |  |  |  | (15,750 | ) |  |  | (37,513 | ) |  |  | 7,991 |  |  |  | 4,554,104 |
2021 |  |  | 11,411,916 |  |  |  | 8,245,180 |  |  |  | 2,859,048 |  |  |  | 3,007 |  |  |  | 22,519,151 |
2020 |  |  | 5,771,045 |  |  |  | 2,890,055 |  |  |  | 357,014 |  |  |  | 5,419 |  |  |  | 9,023,533 |
Compensation Actually Paid vs. Total Shareholder Return [Text Block] |  |  |
Compensation Actually Paid vs. Net Income [Text Block] | Our Net Income grew 28% over the 2019-2022 period reflective of strong growth and performance on our key financial metrics, though Net Income decreased in 2021, reflecting strong revenue growth offset by expenses that were not representative of our normal business operations, followed by an increase in 2022 to a level reflecting overall strong growth from 2020. Net Income performance does not have a strong relationship with the reported CAP to our PEO and Non-PEO NEOs given the lower relative weighting of this measurement of performance as compared to the others previously discussed. |  |
Compensation Actually Paid vs. Company Selected Measure [Text Block] |  |  |
Total Shareholder Return Vs Peer Group [Text Block] |  |  |
Tabular List [Table Text Block] | Tabular List of Most Important Financial Performance Measures The following table presents the financial performance measures that the Company considers to have been the most important in linking CAP to our PEO and Non-PEO NEOs for 2022 to Company performance. The measures in this table are not ranked.
Adjusted Earnings Per Share Growth
Adjusted Operating Income Growth
Total Shareholder Return Amount | $ 148 | 147 | 102
Peer Group Total Shareholder Return Amount | 119 | 133 | 98
Net Income (Loss) | $ 2,589,000,000 | $ 1,308,000,000 | $ 2,018,000,000
Company Selected Measure Amount | 0.12 | 0.22 | 0.07
PEO Name | Gregory C. Case |  |
Measure [Axis]: 1 |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Measure Name | Adjusted Earnings Per Share Growth |  |
Measure [Axis]: 2 |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Measure Name | Adjusted Operating Income Growth |  |
PEO [Member] | Exclusion of Stock Awards and Option Awards [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | $ (17,497,455) | $ (15,262,436) | $ (15,880,566)
PEO [Member] | Inclusion of Equity Values [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 16,426,294 | 95,943,312 | 34,968,905
PEO [Member] | YearEnd Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 16,554,822 | 39,121,312 | 20,945,730
PEO [Member] | Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | (52,980) | 38,650,509 | 12,672,451
PEO [Member] | Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | (83,279) | 18,164,704 | 1,339,915
PEO [Member] | Value of Dividends or Other Earnings Paid on Equity Awards Not Otherwise Included [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 7,731 | 6,787 | 10,809
PEO [Member] | Total Inclusion of Equity Values [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 16,426,294 | 95,943,312 | 34,968,905
Non-PEO NEO [Member] | Exclusion of Change in Pension Value [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 0 | 0 | (76,821)
Non-PEO NEO [Member] | Exclusion of Stock Awards and Option Awards [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | (4,729,173) | (4,583,837) | (4,387,596)
Non-PEO NEO [Member] | Inclusion of Equity Values [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 4,554,104 | 22,519,151 | 9,023,533
Non-PEO NEO [Member] | YearEnd Fair Value of Equity Awards Granted During Year That Remained Unvested as of Last Day of Year [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 4,599,376 | 11,411,916 | 5,771,045
Non-PEO NEO [Member] | Change in Fair Value from Last Day of Prior Year to Last Day of Year of Unvested Equity Awards [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | (15,750) | 8,245,180 | 2,890,055
Non-PEO NEO [Member] | Change in Fair Value from Last Day of Prior Year to Vesting Date of Unvested Equity Awards that Vested During Year [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | (37,513) | 2,859,048 | 357,014
Non-PEO NEO [Member] | Value of Dividends or Other Earnings Paid on Equity Awards Not Otherwise Included [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 7,991 | 3,007 | 5,419
Non-PEO NEO [Member] | Total Inclusion of Equity Values [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | $ 4,554,104 | $ 22,519,151 | $ 9,023,533

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_AdjToCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_AdjToNonPeoNeoCompFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_AdjToPeoCompFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph vi + Details
Name: | ecd_CoSelectedMeasureAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph vi + Details
Name: | ecd_CoSelectedMeasureName
Namespace Prefix: | ecd_
Data Type: | xbrli:normalizedStringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph iii + Details
Name: | ecd_CompActuallyPaidVsCoSelectedMeasureTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph ii + Details
Name: | ecd_CompActuallyPaidVsNetIncomeTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph i + Details
Name: | ecd_CompActuallyPaidVsTotalShareholderRtnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph vi + Details
Name: | ecd_MeasureName
Namespace Prefix: | ecd_
Data Type: | xbrli:normalizedStringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_NamedExecutiveOfficersFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iii + Details
Name: | ecd_NonPeoNeoAvgCompActuallyPaidAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph ii + Details
Name: | ecd_NonPeoNeoAvgTotalCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iv + Details
Name: | ecd_PeerGroupIssuersFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iv + Details
Name: | ecd_PeerGroupTotalShareholderRtnAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iii + Details
Name: | ecd_PeoActuallyPaidCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_PeoName
Namespace Prefix: | ecd_
Data Type: | xbrli:normalizedStringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph ii + Details
Name: | ecd_PeoTotalCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 1 + Details
Name: | ecd_PvpTable
Namespace Prefix: | ecd_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 1 + Details
Name: | ecd_PvpTableTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 6 + Details
Name: | ecd_TabularListTableTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iv + Details
Name: | ecd_TotalShareholderRtnAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph iv + Details
Name: | ecd_TotalShareholderRtnVsPeerGroupTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(20)) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 9 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 17: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 60B -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126958026&loc=SL5780133-109256 Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 8 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794 Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669619-108580 Reference 25: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 31 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8924-108599 Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 11 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794 Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 11 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 7 -URI https://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760 Reference 29: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669625-108580 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 31: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 32: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 33: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 34: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599 Reference 35: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ecd_MeasureAxis=1
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_MeasureAxis=2
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_ExecutiveCategoryAxis=ecd_PeoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=aon_ExclusionOfStockAwardsAndOptionAwardsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=aon_InclusionOfEquityValuesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=aon_yearendFairValueOfEquityAwardsGrantedDuringYearThatRemainedUnvestedAsOfLastDayOfYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=aon_ChangeInFairValueFromLastDayOfPriorYearToLastDayOfYearOfUnvestedEquityAwardsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=aon_ChangeInFairValueFromLastDayOfPriorYearToVestingDateOfUnvestedEquityAwardsThatVestedDuringYearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=aon_ValueOfDividendsOrOtherEarningsPaidOnEquityAwardsNotOtherwiseIncludedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=aon_TotalInclusionOfEquityValuesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_ExecutiveCategoryAxis=ecd_NonPeoNeoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=aon_ExclusionOfChangeInPensionValueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |