Basis of Presentation (Notes)	6 Months Ended
Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The unaudited Consolidated Financial Statements have been prepared by The Interpublic Group of Companies, Inc. and its subsidiaries (the "Company," "IPG," "we," "us" or "our") in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and pursuant to the rules and regulations of the Securities and Exchange Commission (the "SEC") for reporting interim financial information on Form 10-Q. Accordingly, they do not include certain information and disclosures required for complete financial statements. The preparation of financial statements in conformity with U.S. GAAP requires us to make judgments, assumptions and estimates that affect the amounts reported and disclosed. Actual results could differ from these estimates and assumptions. The consolidated results for interim periods are not necessarily indicative of results for the full year and should be read in conjunction with our 2017 Annual Report on Form 10-K. As of January 1, 2018, the Company has revised the presentation of its Consolidated Statements of Operations, which disaggregates net revenue and billable expenses within total revenue and separately presents cost of services; selling, general and administrative expenses; and depreciation and amortization within operating expenses. The revised presentation does not impact total revenue, operating expenses or operating income. Cost of services is comprised of the expenses of our revenue-producing operating segments, Integrated Agency Networks ("IAN") and Constituency Management Group ("CMG"), including salaries and related expenses, office and other direct expenses and billable expenses, and includes an allocation of the centrally managed expenses of our Corporate and other group. Office and other direct expenses include rent expense, professional fees, certain expenses incurred by our staff in servicing our clients and other costs directly attributable to client engagements. Selling, general and administrative expenses are primarily the unallocated expenses of our Corporate and other group, as disclosed further in Note 12, excluding depreciation and amortization. Depreciation and amortization of the fixed assets and intangible assets of the Company is disclosed as a separate operating expense. In the opinion of management, these unaudited Consolidated Financial Statements include all adjustments, consisting only of normal and recurring adjustments necessary for a fair statement of the information for each period contained therein. Certain reclassifications and immaterial revisions have been made to prior-period financial statements to conform to the current-period presentation.

Basis of Presentation

The unaudited Consolidated Financial Statements have been prepared by The Interpublic Group of Companies, Inc. and its subsidiaries (the "Company," "IPG," "we," "us" or "our") in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") and pursuant to the rules and regulations of the Securities and Exchange Commission (the "SEC") for reporting interim financial information on Form 10-Q. Accordingly, they do not include certain information and disclosures required for complete financial statements. The preparation of financial statements in conformity with U.S. GAAP requires us to make judgments, assumptions and estimates that affect the amounts reported and disclosed. Actual results could differ from these estimates and assumptions. The consolidated results for interim periods are not necessarily indicative of results for the full year and should be read in conjunction with our 2017 Annual Report on Form 10-K.

As of January 1, 2018, the Company has revised the presentation of its Consolidated Statements of Operations, which disaggregates net revenue and billable expenses within total revenue and separately presents cost of services; selling, general and administrative expenses; and depreciation and amortization within operating expenses. The revised presentation does not impact total revenue, operating expenses or operating income.

Cost of services is comprised of the expenses of our revenue-producing operating segments, Integrated Agency Networks ("IAN") and Constituency Management Group ("CMG"), including salaries and related expenses, office and other direct expenses and billable expenses, and includes an allocation of the centrally managed expenses of our Corporate and other group. Office and other direct expenses include rent expense, professional fees, certain expenses incurred by our staff in servicing our clients and other costs directly attributable to client engagements.

Selling, general and administrative expenses are primarily the unallocated expenses of our Corporate and other group, as disclosed further in Note 12, excluding depreciation and amortization.

Depreciation and amortization of the fixed assets and intangible assets of the Company is disclosed as a separate operating expense.

In the opinion of management, these unaudited Consolidated Financial Statements include all adjustments, consisting only of normal and recurring adjustments necessary for a fair statement of the information for each period contained therein. Certain reclassifications and immaterial revisions have been made to prior-period financial statements to conform to the current-period presentation.