Organization and Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries. The unaudited condensed consolidated financial statements do not include all of the information required by accounting principles generally accepted in the United States (“GAAP”). The Condensed Consolidated Balance Sheet at December 31, 2021 was derived from the audited Consolidated Balance Sheet at that date and does not include all the disclosures required by GAAP. In the opinion of management, all adjustments which are of a normal recurring nature and necessary for a fair statement of the results as of June 30, 2022 and for the three and six months ended June 30, 2022 and 2021 have been reflected in the condensed consolidated financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements as of and for the year ended December 31, 2021 and the related footnotes thereto. Operating results for the three and six months ended June 30, 2022 are not necessarily indicative of the results to be expected during the remainder of the current year or for any future period.
COVID-19 Pandemic	COVID-19 Pandemic Beginning in March 2020 and continuing through the first quarter of 2021, the Company's services experienced the most severe effects from reductions in client spending due to the economic impact related to the COVID-19 pandemic. While mixed by services and geography, the spending reductions impacted all of the Company's services and markets. Globally, the most impacted services were the Company's experiential services. Most services began to recover in April 2021, and the recovery has continued through the second quarter of 2022.
Impact of the War in Ukraine	Impact of the War in Ukraine The Company has a minority interest in a European company that has majority-ownership interests in local agencies in Russia. During the first quarter of 2022, the war in Ukraine resulted in the imposition of sanctions by the United States, the United Kingdom, and the European Union, that affect the cross-border operations of businesses operating in Russia. In addition, Russian regulators have imposed currency restrictions and regulations that created uncertainty regarding the Company's ability to recover its investment in operations in Russia, as well as the Company's ability to exercise control or influence over operations by the local agencies in Russia. As a result, the Company intends to use its influence to cause the European company to dispose of its ownership interests in the local agencies in Russia. Accordingly, the Company recorded pretax charges of $2.8 million in the first quarter of 2022, primarily consisting of its proportionate share of the net investment in its Russian interest in “Selling, general, and administrative expenses” in the Condensed Consolidated Statements of Operations and Comprehensive Income (Loss).
Recent Accounting Standards	Recent Accounting Standards Accounting Standards Recently Adopted by the Company In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. This guidance provides optional expedients and exceptions for GAAP to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate (“LIBOR”) or another reference rate if certain criteria are met. The amendments in this update are effective for reporting periods that include or are subsequent to March 12, 2020 and must be applied prospectively to contract modifications and hedging relationships through December 31, 2022. On April 1, 2022, the Company adopted the standard prospectively and determined that the adoption of this accounting guidance did not have a material impact on its condensed consolidated financial statements. On January 1, 2022, the Company adopted ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (“ASU 2020-06”), which simplifies accounting for convertible instruments by removing major separation models required under current GAAP, simplifies the contract settlement assessment for equity classification, requires the use of the if-converted method for all convertible instruments in the diluted earnings per share calculation and expands disclosure requirements. The adoption of this accounting standard, under the full retrospective method, did not have a material impact on the Company's condensed consolidated financial statements and use of the if-converted method did not have an impact on the Company's overall earnings per share calculation. On January 1, 2022, the Company adopted ASU 2021-04, Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation—Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options (a consensus of the FASB Emerging Issues Task Force). The guidance clarifies certain aspects of the current guidance to promote consistency among reporting of an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options (for example, warrants) that remain equity classified after modification or exchange. The guidance is applied prospectively to all modifications or exchanges that occur on or after the date of adoption and the adoption of this accounting standard did not have a material impact on the Company's condensed consolidated financial statements. On January 1, 2022, the Company adopted ASU 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance. This update requires annual disclosures about transactions with a government that are accounted for by applying a grant or contribution accounting model by analogy. The guidance is applied prospectively to all transactions within the scope of the amendments that are reflected in financial statements at the date of initial application and new transactions that are entered into after the date of initial application. The adoption of this accounting standard did not have a material impact on the Company's condensed consolidated financial statements. Accounting Standards Recently Issued but Not Yet Adopted by the Company In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 606): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers, which requires that an entity recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Topic 606 as if it had originated the contracts. Generally, this should result in an acquirer recognizing and measuring the acquired contract assets and contract liabilities consistent with how they were recognized and measured in the acquiree’s financial statements, if the acquiree prepared financial statements in accordance with GAAP. The amendment in this update is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The guidance should be applied prospectively to business combinations occurring on or after the effective date of the amendment in this update. The Company is evaluating the potential impact of this adoption on its consolidated financial statements. All other new accounting pronouncements issued, but not yet effective or adopted have been deemed to be not relevant to the Company and, accordingly, are not expected to have a material impact once adopted.

Organization and Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2022

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries. The unaudited condensed consolidated financial statements do not include all of the information required by accounting principles generally accepted in the United States (“GAAP”). The Condensed Consolidated Balance Sheet at December 31, 2021 was derived from the audited Consolidated Balance Sheet at that date and does not include all the disclosures required by GAAP. In the opinion of management, all adjustments which are of a normal recurring nature and necessary for a fair statement of the results as of June 30, 2022 and for the three and six months ended June 30, 2022 and 2021 have been reflected in the condensed consolidated financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements as of and for the year ended December 31, 2021 and the related footnotes thereto. Operating results for the three and six months ended June 30, 2022 are not necessarily indicative of the results to be expected during the remainder of the current year or for any future period.

COVID-19 Pandemic

Beginning in March 2020 and continuing through the first quarter of 2021, the Company's services experienced the most severe effects from reductions in client spending due to the economic impact related to the COVID-19 pandemic. While mixed by services and geography, the spending reductions impacted all of the Company's services and markets. Globally, the most impacted services were the Company's experiential services. Most services began to recover in April 2021, and the recovery has continued through the second quarter of 2022.

Impact of the War in Ukraine

The Company has a minority interest in a European company that has majority-ownership interests in local agencies in Russia. During the first quarter of 2022, the war in Ukraine resulted in the imposition of sanctions by the United States, the United Kingdom, and the European Union, that affect the cross-border operations of businesses operating in Russia. In addition, Russian regulators have imposed currency restrictions and regulations that created uncertainty regarding the Company's ability to recover its investment in operations in Russia, as well as the Company's ability to exercise control or influence over operations by the local agencies in Russia. As a result, the Company intends to use its influence to cause the European company to dispose of its ownership interests in the local agencies in Russia. Accordingly, the Company recorded pretax charges of $2.8 million in the first quarter of 2022, primarily consisting of its proportionate share of the net investment in its Russian interest in “Selling, general, and administrative expenses” in the Condensed Consolidated Statements of Operations and Comprehensive Income (Loss).

Recent Accounting Standards

Accounting Standards Recently Adopted by the Company

In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on

Financial Reporting. This guidance provides optional expedients and exceptions for GAAP to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate (“LIBOR”) or another reference rate if certain criteria are met. The amendments in this update are effective for reporting periods that include or are subsequent to March 12, 2020 and must be applied prospectively to contract modifications and hedging relationships through December 31, 2022. On April 1, 2022, the Company adopted the standard prospectively and determined that the adoption of this accounting guidance did not have a material impact on its condensed consolidated financial statements.

On January 1, 2022, the Company adopted ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity (“ASU 2020-06”), which simplifies accounting for convertible instruments by removing major separation models required under current GAAP, simplifies the contract settlement assessment for equity classification, requires the use of the if-converted method for all convertible instruments in the diluted earnings per share calculation and expands disclosure requirements. The adoption of this accounting standard, under the full retrospective method, did not have a material impact on the Company's condensed consolidated financial statements and use of the if-converted method did not have an impact on the Company's overall earnings per share calculation.

On January 1, 2022, the Company adopted ASU 2021-04, Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation—Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options (a consensus of the FASB Emerging Issues Task Force). The guidance clarifies certain aspects of the current guidance to promote consistency among reporting of an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options (for example, warrants) that remain equity classified after modification or exchange. The guidance is applied prospectively to all modifications or exchanges that occur on or after the date of adoption and the adoption of this accounting standard did not have a material impact on the Company's condensed consolidated financial statements.

On January 1, 2022, the Company adopted ASU 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance. This update requires annual disclosures about transactions with a government that are accounted for by applying a grant or contribution accounting model by analogy. The guidance is applied prospectively to all transactions within the scope of the amendments that are reflected in financial statements at the date of initial application and new transactions that are entered into after the date of initial application. The adoption of this accounting standard did not have a material impact on the Company's condensed consolidated financial statements.

Accounting Standards Recently Issued but Not Yet Adopted by the Company

In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 606): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers, which requires that an entity recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Topic 606 as if it had originated the contracts. Generally, this should result in an acquirer recognizing and measuring the acquired contract assets and contract liabilities consistent with how they were recognized and measured in the acquiree’s financial statements, if the acquiree prepared financial statements in accordance with GAAP. The amendment in this update is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. Early adoption is permitted, including adoption in an interim period. The guidance should be applied prospectively to business combinations occurring on or after the effective date of the amendment in this update. The Company is evaluating the potential impact of this adoption on its consolidated financial statements.

All other new accounting pronouncements issued, but not yet effective or adopted have been deemed to be not relevant to the Company and, accordingly, are not expected to have a material impact once adopted.