Principles of Consolidation and Other Matters	9 Months Ended
Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Principles of Consolidation and Other Matters	Principles of Consolidation and Other Matters The consolidated financial statements included herein have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission. While certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been omitted pursuant to such rules and regulations for interim filings, the Company believes that the information and disclosures presented are adequate to make such information and disclosures not misleading. These consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 (the "2019 Form 10-K"). The financial information contained herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the Company’s consolidated financial statements as of and for the three and nine month periods ended September 30, 2020 and 2019. Estimates: The preparation of the consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expense during the reporting period. On an ongoing basis the Company evaluates its estimates, judgments and methodologies. The estimates are based on historical experience and on various other assumptions that the Company believes are reasonable. Such matters include: •the allowance for current expected credit losses on receivables, •estimates of revenue, •impairment assessments and charges, •recoverability of long-lived assets, •liabilities for errors and omissions, •deferred tax assets, uncertain tax positions and income tax expense, •share-based and incentive compensation expense, •useful lives assigned to long-lived assets, and depreciation and amortization, •fair value estimates of contingent consideration receivable or payable related to acquisitions or dispositions The Company believes these estimates are reasonable based on information currently available at the time they are made. Management has made estimates of the impact of COVID-19 within the Company’s financial statements and there may be changes to those estimates in future periods. In most situations where estimates, fair values or recoverability of assets is dependent upon short or long term projections of cash flows, revenues or earnings before interest, taxes, depreciation and amortization ("EBITDA"), the Company has based its projections assuming the gradual lifting of global lockdowns through the rest of 2020 and into 2021. The Company has also considered potential impacts to its customer base in various industries and geographies. The ultimate extent to which the COVID-19 pandemic will directly or indirectly impact the Company’s businesses, results of operations and financial condition will depend on future developments that are highly uncertain, including new information that may emerge concerning COVID-19 and the actions taken to contain it or treat it, and the economic impact on local, regional, national and international customers and markets. Actual results may differ from these estimates. Cash and Cash Equivalents Cash and cash equivalents primarily consist of certificates of deposit and time deposits, with original maturities of three months or less, and money market funds. The estimated fair value of the Company's cash and cash equivalents approximates their carrying value. The Company is required to maintain operating funds primarily related to regulatory requirements outside of the United States or as collateral under captive insurance arrangements. At September 30, 2020, the Company maintained $247 million compared to $197 million at December 31, 2019 related to these regulatory requirements. Allowance for Current Expected Credit Losses on Accounts Receivable The Company’s policy for providing an allowance for current expected credit losses (“CECL”) on its accounts receivable is based on management’s best estimate of amounts that will be uncollectible primarily based on the Company’s historical experience of collections in its various businesses and other events that may affect the net realizable value of receivables. The charge related to expected credit losses was immaterial to the consolidated statement of income in the three and nine month periods ended September 30, 2020. Investments The caption "Investment (loss) income" in the consolidated statements of income comprises realized and unrealized gains and losses from investments recognized in earnings. It includes, when applicable, other than temporary declines in the value of securities, mark-to-market increases or decreases in equity investments with readily determinable fair values and equity method gains or losses on the Company's investments in private equity funds. The Company holds investments in certain private equity funds that are accounted for under the equity method of accounting using a consistently applied three-month lag period adjusted for any known significant changes from the lag period to the reporting date of the Company. The underlying private equity funds follow investment company accounting, where investments within the fund are carried at fair value. Investment gains or losses for the Company's proportionate share of the change in fair value of the funds are recorded in earnings. Investments accounted for using the equity method of accounting are included in "other assets" in the consolidated balance sheets. The Company recorded net investment losses of $14 million and $47 million for the three and nine month periods ended September 30, 2020 compared to net investment income of $7 million and $20 million for the three and nine month periods ended September 30, 2019. The net investment loss reported in the third quarter of 2020 is primarily due to the mark-to-market change related to the Company's investment in Alexander Forbes ("AF"). The net investment loss for the nine months ended September 30, 2020 also includes a loss of $23 million from the sale of shares of AF during the second quarter of 2020, as well as losses related to its private equity fund investments. The three and nine month periods ended September 30, 2019 include gains of $4 million and $10 million related to mark-to-market changes in equity securities and gains of $3 million and $10 million related to investments in private equity funds and other investments. Income Taxes The Company's effective tax rate in the third quarter of 2020 was 30.3% compared with 26.0% in the third quarter of 2019. The effective tax rates for the first nine months of 2020 and 2019 were 26.0% and 27.8%. The rate in the third quarter and first nine months of 2020 reflects costs of re-measuring the Company’s U.K. deferred tax liability for legislation that cancelled a scheduled 2% reduction in the U.K. corporate income tax rate, partially offset by tax benefits related to a new international funding structure implemented to facilitate global staffing and contracting. The rate in the first nine months of 2019 reflects discrete adjustments related to the JLT acquisition, including tax on the disposition of JLT’s aerospace business and nondeductible expenses incurred in connection with the JLT Transaction. The tax rates in both periods reflect the impact of discrete tax items such as excess tax benefits related to share-based compensation, changes in tax legislation, changes in uncertain tax positions, deferred tax adjustments and nontaxable adjustments to contingent acquisition consideration. The Company's tax rate reflects its income, statutory tax rates and tax planning in the various jurisdictions in which it operates. Significant judgment is required in determining the annual effective tax rate and in evaluating uncertain tax positions. Losses in one jurisdiction, generally, cannot offset earnings in another, and within certain jurisdictions profits and losses may not offset between entities. Consequently, losses in certain jurisdictions may require valuation allowances affecting the effective tax rate, depending on estimates of the realizability of associated deferred tax assets. The tax rate is also sensitive to changes in unrecognized tax benefits, including the impact of settled tax audits and expired statutes of limitation. Changes in tax laws or tax rulings may have a significant impact on our effective tax rate. The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in tax returns. The Company's gross unrecognized tax benefits increased from $86 million at December 31, 2019 to $102 million at September 30, 2020 due to net changes to tax positions of prior years and current year accruals, offset by expirations of statutes of limitation. It is reasonably possible that the total amount of unrecognized tax benefits will decrease between zero and approximately $22 million within the next twelve months due to settlements of audits and expirations of statutes of limitation. Integration and Restructuring Charges Severance and related costs are recognized based on amounts due under established severance plans or estimates of one-time benefits that will be provided. Typically, severance benefits are recognized when the impacted colleagues are notified of their expected termination and such termination is expected to occur within the legally required notification period. These costs are included in compensation and benefits in the consolidated statements of income. Costs for real estate consolidation are recognized based on the type of cost, and the expected future use of the facility. For locations where the Company does not expect to sub-lease the property, the amortization of any right-of-use asset is accelerated from the decision date to the cease use date. For locations where the Company expects to sub-lease the properties subsequent to its vacating the property, the right-of-use asset is reviewed for potential impairment at the earlier of the cease use date or the date a sub-lease is signed. To determine the amount of impairment, the fair value of the right-of-use asset is determined based on the present value of the estimated net cash flows related to the property. Contractual costs outside of the right-of-use asset are recognized based on the net present value of expected future cash outflows for which the Company will not receive any benefit. Such amounts are reliant on estimates of future sub-lease income to be received and future contractual costs to be incurred. These costs are included in other operating expenses in the consolidated statements of income. Other costs related to integration and restructuring, such as moving, legal or consulting costs are recognized as incurred. These costs are included in other operating expenses in the consolidated statements of income.

The consolidated financial statements included herein have been prepared by the Company pursuant to the rules and regulations of the Securities and Exchange Commission. While certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America have been omitted pursuant to such rules and regulations for interim filings, the Company believes that the information and disclosures presented are adequate to make such information and disclosures not misleading. These consolidated financial statements should be read in conjunction with the consolidated financial statements and the notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019 (the "2019 Form 10-K").

The financial information contained herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the Company’s consolidated financial statements as of and for the three and nine month periods ended September 30, 2020 and 2019.

Estimates: The preparation of the consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expense during the reporting period. On an ongoing basis the Company evaluates its estimates, judgments and methodologies. The estimates are based on historical experience and on various other assumptions that the Company believes are reasonable. Such matters include:

The Company believes these estimates are reasonable based on information currently available at the time they are made. Management has made estimates of the impact of COVID-19 within the Company’s financial statements and there may be changes to those estimates in future periods. In most situations where estimates, fair values or recoverability of assets is dependent upon short or long term projections of cash flows, revenues or earnings before interest, taxes, depreciation and amortization ("EBITDA"), the Company has based its projections assuming the gradual lifting of global lockdowns through the rest of 2020 and into 2021. The Company has also considered potential impacts to its customer base in various industries and geographies. The ultimate extent to which the COVID-19 pandemic will directly or indirectly impact the Company’s businesses, results of operations and financial condition will depend on future developments that are highly uncertain, including new information that may emerge concerning COVID-19 and the actions taken to contain it or treat it, and the economic impact on local, regional, national and international customers and markets. Actual results may differ from these estimates.

Cash and cash equivalents primarily consist of certificates of deposit and time deposits, with original maturities of three months or less, and money market funds. The estimated fair value of the Company's cash and cash equivalents approximates their carrying value. The Company is required to maintain operating funds primarily related to regulatory requirements outside of the United States or as collateral under captive insurance arrangements. At September 30, 2020, the Company maintained $247 million compared to $197 million at December 31, 2019 related to these regulatory requirements.

The Company’s policy for providing an allowance for current expected credit losses (“CECL”) on its accounts receivable is based on management’s best estimate of amounts that will be uncollectible primarily based on the Company’s historical experience of collections in its various businesses and other events that may affect the net realizable value of receivables. The charge related to expected credit losses was immaterial to the consolidated statement of income in the three and nine month periods ended September 30, 2020.

The caption "Investment (loss) income" in the consolidated statements of income comprises realized and unrealized gains and losses from investments recognized in earnings. It includes, when applicable, other than temporary declines in the value of securities, mark-to-market increases or decreases in equity investments with readily determinable fair values and equity method gains or losses on the Company's investments in private equity funds.

The Company holds investments in certain private equity funds that are accounted for under the equity method of accounting using a consistently applied three-month lag period adjusted for any known significant changes from the lag period to the reporting date of the Company. The underlying private equity funds follow investment company accounting, where investments within the fund are carried at fair value. Investment gains or losses for the Company's proportionate share of the change in fair value of the funds are recorded in earnings. Investments

The Company recorded net investment losses of $14 million and $47 million for the three and nine month periods ended September 30, 2020 compared to net investment income of $7 million and $20 million for the three and nine month periods ended September 30, 2019. The net investment loss reported in the third quarter of 2020 is primarily due to the mark-to-market change related to the Company's investment in Alexander Forbes ("AF"). The net investment loss for the nine months ended September 30, 2020 also includes a loss of $23 million from the sale of shares of AF during the second quarter of 2020, as well as losses related to its private equity fund investments. The three and nine month periods ended September 30, 2019 include gains of $4 million and $10 million related to mark-to-market changes in equity securities and gains of $3 million and $10 million related to investments in private equity funds and other investments.

The Company's effective tax rate in the third quarter of 2020 was 30.3% compared with 26.0% in the third quarter of 2019. The effective tax rates for the first nine months of 2020 and 2019 were 26.0% and 27.8%. The rate in the third quarter and first nine months of 2020 reflects costs of re-measuring the Company’s U.K. deferred tax liability for legislation that cancelled a scheduled 2% reduction in the U.K. corporate income tax rate, partially offset by tax benefits related to a new international funding structure implemented to facilitate global staffing and contracting.

The rate in the first nine months of 2019 reflects discrete adjustments related to the JLT acquisition, including tax on the disposition of JLT’s aerospace business and nondeductible expenses incurred in connection with the JLT Transaction. The tax rates in both periods reflect the impact of discrete tax items such as excess tax benefits related to share-based compensation, changes in tax legislation, changes in uncertain tax positions, deferred tax adjustments and nontaxable adjustments to contingent acquisition consideration.

The Company's tax rate reflects its income, statutory tax rates and tax planning in the various jurisdictions in which it operates. Significant judgment is required in determining the annual effective tax rate and in evaluating uncertain tax positions.

Losses in one jurisdiction, generally, cannot offset earnings in another, and within certain jurisdictions profits and losses may not offset between entities. Consequently, losses in certain jurisdictions may require valuation allowances affecting the effective tax rate, depending on estimates of the realizability of associated deferred tax assets. The tax rate is also sensitive to changes in unrecognized tax benefits, including the impact of settled tax audits and expired statutes of limitation.

Changes in tax laws or tax rulings may have a significant impact on our effective tax rate. The Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in tax returns. The Company's gross unrecognized tax benefits increased from $86 million at December 31, 2019 to $102 million at September 30, 2020 due to net changes to tax positions of prior years and current year accruals, offset by expirations of statutes of limitation. It is reasonably possible that the total amount of unrecognized tax benefits will decrease between zero and approximately $22 million within the next twelve months due to settlements of audits and expirations of statutes of limitation.

Severance and related costs are recognized based on amounts due under established severance plans or estimates of one-time benefits that will be provided. Typically, severance benefits are recognized when the impacted colleagues are notified of their expected termination and such termination is expected to occur within the legally required notification period. These costs are included in compensation and benefits in the consolidated statements of income.

Costs for real estate consolidation are recognized based on the type of cost, and the expected future use of the facility. For locations where the Company does not expect to sub-lease the property, the amortization of any right-of-use asset is accelerated from the decision date to the cease use date. For locations where the Company expects to sub-lease the properties subsequent to its vacating the property, the right-of-use asset is reviewed for potential impairment at the earlier of the cease use date or the date a sub-lease is signed. To determine the amount of impairment, the fair value of the right-of-use asset is determined based on the present value of the estimated net cash flows related to the property. Contractual costs outside of the right-of-use asset are recognized based on the net present value of expected future cash outflows for which the Company will not receive any benefit. Such amounts are reliant on estimates of future sub-lease income to be received and future contractual costs to be incurred. These costs are included in other operating expenses in the consolidated statements of income.